Method for determining orientation of contour line segment in local area and for determining straight line and corner

Claim 1

A method for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in a plurality of orientations around one of pixels, located in the local area and having said first predetermined value, wherein the pixels are stored in the storage memory unit; and a second step for determining that a local line segment exists in an orientation in which the number of pixels located in the orientation is greater than a second predetermined value using the processing unit.

Claim 2

A method for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in a plurality of orientations around one of pixels, located in the local area and having said first predetermined value, wherein the pixels are stored in the storage memory unit; and a second step for determining that a local line segment exists in an orientation in which the number of pixels located in the orientation is greater than a second predetermined value using the processing unit.

Claim 10

A method for determining an orientation of a local line segment included in a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; and a second step for determining in each of the plurality of local areas that a local line segment exists in an orientation in which the number of pixels located in the orientation is greater than a second predetermined value using the processing unit.

Claim 11

A method for determining an orientation of a local line segment included in a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; and a second step for determining in each of the plurality of local areas that a local line segment exists in an orientation in which the number of pixels located in the orientation is greater than a second predetermined value using the processing unit.

Claim 13

A method for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels located in a plurality of orientations around one of pixels, located in the local area and having a first predetermined value, wherein the pixels are stored in a storage memory unit; a second step for determining whether or not the number of pixels located in each orientation is greater than a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit; and a third step for determining that a local line segment exists in said each orientation when the number of pixels located in each orientation is greater than a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit.

Claim 14

A method for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels located in a plurality of orientations around one of pixels, located in the local area and having a first predetermined value, wherein the pixels are stored in a storage memory unit; a second step for determining whether or not the number of pixels located in each orientation is greater than a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit; and a third step for determining that a local line segment exists in said each orientation when the number of pixels located in each orientation is greater than a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit.

Claim 17

A method for determining an orientation of a local line segment included in a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; and a second step for determining whether or not the number of pixels located in each orientation is greater than a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit; and a third step for determining that a local line segment exists in said each orientation when the number of pixels located in each orientation is greater than a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit.

Claim 18

A method for determining an orientation of a local line segment included in a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; and a second step for determining whether or not the number of pixels located in each orientation is greater than a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit; and a third step for determining that a local line segment exists in said each orientation when the number of pixels located in each orientation is greater than a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit.

Claim 19

A method for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels located in a plurality of orientations around one of pixels located in the local area and having a first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for obtaining a difference between the number of pixels located in each orientation and a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit; and a third step for determining that a local line segment exists in a certain orientation when the difference for the orientation is greater than a second predetermined value using the processing unit.

Claim 20

A method for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels located in a plurality of orientations around one of pixels located in the local area and having a first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for obtaining a difference between the number of pixels located in each orientation and a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit; and a third step for determining that a local line segment exists in a certain orientation when the difference for the orientation is greater than a second predetermined value using the processing unit.

Claim 22

A method for determining an orientation of a local line segment included in a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; and a second step for obtaining a difference between the number of pixels located in each orientation and a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit; and a third step for determining that a local line segment exists in a certain orientation when the difference for the orientation is greater than a second predetermined value using the processing unit.

Claim 23

A method for determining an orientation of a local line segment included in a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; and a second step for obtaining a difference between the number of pixels located in each orientation and a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit; and a third step for determining that a local line segment exists in a certain orientation when the difference for the orientation is greater than a second predetermined value using the processing unit.

Claim 24

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for counting the numbers of pixels each having a first predetermined value and located in each of a first plurality of sectorial areas around each pixel having the first predetermined value and located at the center of each of a plurality of local areas, and counting the numbers of pixels each having the first predetermined value and located in each of a second plurality of sectorial areas around said each pixel having the first predetermined value and located at the center of each of the plurality of local areas, where the locations of the second plurality of sectorial areas are different from the locations of the first plurality of sectorial areas, wherein the pixels are stored in the storage memory unit; a second step for obtaining for each of the first and second patterns a difference between the number of pixels located in each orientation and a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit; a third step for obtaining for each of the first and second patterns an orientation corresponding to one of the areas for which the difference is greater than a second predetermined value using the processing unit; and a fourth step for obtaining an overlapping area in which one of the first plurality of sectorial areas and one of the second plurality of sectorial areas are overlapped, where the number of pixels located in said one of the first plurality of sectorial areas is greater than the second predetermined value, and the number of pixels located in said one of the second plurality of sectorial areas is greater than the second predetermined value, respectively; and for determining that a local line segment exists in an orientation corresponding to said overlapping area using the processing unit.

Claim 25

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for counting the numbers of pixels each having a first predetermined value and located in each of a first plurality of sectorial areas around each pixel having the first predetermined value and located at the center of each of a plurality of local areas, and counting the numbers of pixels each having the first predetermined value and located in each of a second plurality of sectorial areas around said each pixel having the first predetermined value and located at the center of each of the plurality of local areas, where the locations of the second plurality of sectorial areas are different from the locations of the first plurality of sectorial areas, wherein the pixels are stored in the storage memory unit; a second step for obtaining for each of the first and second patterns a difference between the number of pixels located in each orientation and a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit; a third step for obtaining for each of the first and second patterns an orientation corresponding to one of the areas for which the difference is greater than a second predetermined value using the processing unit; and a fourth step for obtaining an overlapping area in which one of the first plurality of sectorial areas and one of the second plurality of sectorial areas are overlapped, where the number of pixels located in said one of the first plurality of sectorial areas is greater than the second predetermined value, and the number of pixels located in said one of the second plurality of sectorial areas is greater than the second predetermined value, respectively; and for determining that a local line segment exists in an orientation corresponding to said overlapping area using the processing unit.

Claim 26

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in each of a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value wherein the pixels are stored in the storage memory unit; a second step for determining in each of the plurality of local areas that a local line segment exists in a certain orientation when the number of pixels located in the orientation is greater than a second predetermined value using the processing unit; a third step for determining in each of the plurality of local areas that a straight local line segment passing through said each of the plurality of pixels exists in the local area when two local line segments are determined to exist in the second step, and the orientations of the two local line segments differ by 180° from each other using the processing unit; and a fourth step for determining a group of pixels as a candidate of a line segment when the pixels in the group are contiguously arrayed and it is determined in the third step that local line segments in the same orientation pass through the respective pixels in the respective local areas using the processing unit.

Claim 27

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in each of a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value wherein the pixels are stored in the storage memory unit; a second step for determining in each of the plurality of local areas that a local line segment exists in a certain orientation when the number of pixels located in the orientation is greater than a second predetermined value using the processing unit; a third step for determining in each of the plurality of local areas that a straight local line segment passing through said each of the plurality of pixels exists in the local area when two local line segments are determined to exist in the second step, and the orientations of the two local line segments differ by 180° from each other using the processing unit; and a fourth step for determining a group of pixels as a candidate of a line segment when the pixels in the group are contiguously arrayed and it is determined in the third step that local line segments in the same orientation pass through the respective pixels in the respective local areas using the processing unit.

Claim 36

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for counting the numbers of pixels each having a first predetermined value and located in each of a plurality of sectorial areas around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for determining in each of the plurality of local areas that a local line segment exists in an orientation corresponding to one of the sectorial areas when the number of pixels located in the sectorial area is greater than a second predetermined value using the processing unit; a third step for determining in each of the plurality of local areas that a straight local line segment passing through said each of the plurality of pixels exists in the local area when two local line segments are determined to exist in the second step, and the orientations of the two local line segments differ by 180° from each other using the processing unit; and a fourth step for determining a group of pixels as a candidate of a line segment when the pixels in the group are contiguously arrayed and it is determined in the third step that local line segments in the same orientation pass through the respective pixels in the respective local areas using the processing unit.

Claim 37

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for counting the numbers of pixels each having a first predetermined value and located in each of a plurality of sectorial areas around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for determining in each of the plurality of local areas that a local line segment exists in an orientation corresponding to one of the sectorial areas when the number of pixels located in the sectorial area is greater than a second predetermined value using the processing unit; a third step for determining in each of the plurality of local areas that a straight local line segment passing through said each of the plurality of pixels exists in the local area when two local line segments are determined to exist in the second step, and the orientations of the two local line segments differ by 180° from each other using the processing unit; and a fourth step for determining a group of pixels as a candidate of a line segment when the pixels in the group are contiguously arrayed and it is determined in the third step that local line segments in the same orientation pass through the respective pixels in the respective local areas using the processing unit.

Claim 38

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for counting the numbers of pixels each having a first predetermined value and located in each of a first plurality of sectorial areas around each pixel having the first predetermined value and located at the center of each of a plurality of local areas, and counting the numbers of pixels each having the first predetermined value and located in each of second plurality of sectorial areas around said each pixel having the first predetermined value and located at the center of each of the plurality of local areas, where the locations of the second plurality of sectorial areas are different from the locations of the first plurality of sectorial areas, wherein the pixels are stored in the storage memory unit; a second step for obtaining an overlapping area in which one of the first plurality of sectorial areas and one of the second plurality of sectorial areas are overlapped, where the number of pixels located in said one of the first plurality of sectorial areas is greater than a second predetermined value, and the number of pixels located in said one of the second plurality of sectorial areas is greater than the second predetermined value, respectively; and for determining that a local line segment exists in an orientation corresponding to said overlapping area using the processing unit; a third step for determining in each of the plurality of local areas that a straight local line segment passing through said each pixel exists in the local area when two local line segments are determined to exist in the second step, and the orientations of the two local line segments differ by 180° from each other using the processing unit; and a fourth step for determining a group of pixels as a candidate of a line segment when the pixels in the group are contiguously arrayed and it is determined in the fourth step that local line segments in the same orientation pass through the respective pixels in the respective local areas using the processing unit.

Claim 39

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit, comprising: a first step for counting the numbers of pixels each having a first predetermined value and located in each of a first plurality of sectorial areas around each pixel having the first predetermined value and located at the center of each of a plurality of local areas, and counting the numbers of pixels each having the first predetermined value and located in each of second plurality of sectorial areas around said each pixel having the first predetermined value and located at the center of each of the plurality of local areas, where the locations of the second plurality of sectorial areas are different from the locations of the first plurality of sectorial areas, wherein the pixels are stored in the storage memory unit; a second step for obtaining an overlapping area in which one of the first plurality of sectorial areas and one of the second plurality of sectorial areas are overlapped, where the number of pixels located in said one of the first plurality of sectorial areas is greater than a second predetermined value, and the number of pixels located in said one of the second plurality of sectorial areas is greater than the second predetermined value, respectively; and for determining that a local line segment exists in an orientation corresponding to said overlapping area using the processing unit; a third step for determining in each of the plurality of local areas that a straight local line segment passing through said each pixel exists in the local area when two local line segments are determined to exist in the second step, and the orientations of the two local line segments differ by 180° from each other using the processing unit; and a fourth step for determining a group of pixels as a candidate of a line segment when the pixels in the group are contiguously arrayed and it is determined in the fourth step that local line segments in the same orientation pass through the respective pixels in the respective local areas using the processing unit.

Claim 40

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage means unit, comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in each of a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value wherein the pixels are stored in the storage memory unit; a second step for obtaining a difference between the number of pixels located in each orientation and a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit; a third step for determining that a local line segment exists in a certain orientation when the difference for the orientation is greater than a second predetermined value using the processing unit; a fourth step for determining in each of the plurality of local areas that a straight local line segment passing through said each of the plurality of pixels exists in the local area when two local line segments are determined to exist in the third step, and the orientations of the two local line segments differ by 180° from each other using the processing unit; and a fifth step for determining a group of pixels as a candidate of a line segment when the pixels in the group are contiguously arrayed and it is determined in the fourth step that local line segments in the same orientation pass through the respective pixels in the respective local areas using the processing unit.

Claim 41

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage means unit, comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in each of a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value wherein the pixels are stored in the storage memory unit; a second step for obtaining a difference between the number of pixels located in each orientation and a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the processing unit; a third step for determining that a local line segment exists in a certain orientation when the difference for the orientation is greater than a second predetermined value using the processing unit; a fourth step for determining in each of the plurality of local areas that a straight local line segment passing through said each of the plurality of pixels exists in the local area when two local line segments are determined to exist in the third step, and the orientations of the two local line segments differ by 180° from each other using the processing unit; and a fifth step for determining a group of pixels as a candidate of a line segment when the pixels in the group are contiguously arrayed and it is determined in the fourth step that local line segments in the same orientation pass through the respective pixels in the respective local areas using the processing unit.

Claim 42

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for counting the numbers of pixels each having a first predetermined value and located in each of a plurality of sectorial areas around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for obtaining a difference between the number of pixels located in each area and a sum of the numbers of pixels in orientations adjacent to said each areas on both sides thereof using the processing unit; a third step for determining that a local line segment exists in an orientation of one of the areas when the difference for the area is greater than a second predetermined value using the processing unit; a fourth step for determining in each of the plurality of local areas that a straight local line segment passing through said each of the plurality of pixels exists in the local area when two local line segments are determined to exist in the third step, and the orientations of the two local line segments differ by 180° from each other using the processing unit; and a fifth step for determining a group of pixels as a candidate of a line segment when the pixels in the group are contiguously arrayed and it is determined in the fourth step that local line segments in the same orientation pass through the respective pixels in the respective local areas using the processing unit.

Claim 43

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for counting the numbers of pixels each having a first predetermined value and located in each of a plurality of sectorial areas around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for obtaining a difference between the number of pixels located in each area and a sum of the numbers of pixels in orientations adjacent to said each areas on both sides thereof using the processing unit; a third step for determining that a local line segment exists in an orientation of one of the areas when the difference for the area is greater than a second predetermined value using the processing unit; a fourth step for determining in each of the plurality of local areas that a straight local line segment passing through said each of the plurality of pixels exists in the local area when two local line segments are determined to exist in the third step, and the orientations of the two local line segments differ by 180° from each other using the processing unit; and a fifth step for determining a group of pixels as a candidate of a line segment when the pixels in the group are contiguously arrayed and it is determined in the fourth step that local line segments in the same orientation pass through the respective pixels in the respective local areas using the processing unit.

Claim 44

A method for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in each of a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for determining in each of the plurality of local areas that a local line segment exists in an orientation corresponding to one of the sectorial areas when the number of pixels located in the sectorial area is greater than a second predetermined value using the processing unit; a third step for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined in the second step exceeds a predetermined angle value using the processing unit; a fourth step for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously using the processing unit; a fifth step for obtaining for each group representative values of the coordinates of the respective pixels in the group using the processing unit; a sixth step for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group using the processing unit; and a seventh step for obtaining a representative value of the orientations of all of the pixels in each group using the processing unit.

Claim 45

A method for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in each of a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for determining in each of the plurality of local areas that a local line segment exists in an orientation corresponding to one of the sectorial areas when the number of pixels located in the sectorial area is greater than a second predetermined value using the processing unit; a third step for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined in the second step exceeds a predetermined angle value using the processing unit; a fourth step for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously using the processing unit; a fifth step for obtaining for each group representative values of the coordinates of the respective pixels in the group using the processing unit; a sixth step for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group using the processing unit; and a seventh step for obtaining a representative value of the orientations of all of the pixels in each group using the processing unit.

Claim 50

A method for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in each of a plurality of sectorial areas around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for determining in each of the plurality of local areas that a local line segment exists in an orientation corresponding to one of the sectorial areas when the number of pixels located in the sectorial area is greater than a second predetermined value used in the processing unit; a third step for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined in the second step exceeds a predetermined angle value used in the processing unit; a fourth step for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously used in the processing unit: a fifth step for obtaining for each group representative values of the coordinates of the respective pixels in the group used in the processing unit; a sixth step for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group used in the processing unit; and a seventh step for obtaining a representative value of the orientations of all of the pixels in each group used in the processing unit.

Claim 51

A method for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in each of a plurality of sectorial areas around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for determining in each of the plurality of local areas that a local line segment exists in an orientation corresponding to one of the sectorial areas when the number of pixels located in the sectorial area is greater than a second predetermined value used in the processing unit; a third step for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined in the second step exceeds a predetermined angle value used in the processing unit; a fourth step for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously used in the processing unit: a fifth step for obtaining for each group representative values of the coordinates of the respective pixels in the group used in the processing unit; a sixth step for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group used in the processing unit; and a seventh step for obtaining a representative value of the orientations of all of the pixels in each group used in the processing unit.

Claim 52

A method for detecting a position of a corner from a contour in a binary contour image implemented by a central processing unit accessing a storage memory unit comprising: a first step for counting the numbers of pixels each having a first predetermined value and located in each of a first plurality of sectorial areas around each pixel having the first predetermined value and located at the center of each of a plurality of local areas, and counting the numbers of pixels each having the first predetermined value and located in each of a second plurality of sectorial areas around said each pixel having the first predetermined value and located at the center of each of the plurality of local areas, where the locations of the second plurality of sectorial areas are different from the locations of the first plurality of sectorial areas, wherein the pixels are stored in the storage memory unit; a second step for obtaining two overlapping areas in each of which one of the first plurality of sectorial areas and one of the second plurality of sectorial areas are overlapped, where the number of pixels located in said one of the first plurality of sectorial areas is greater than a second predetermined value, and the number of pixels located in said one of the second plurality of sectorial areas is greater than the second predetermined value, respectively: and for determining that a local line segment exists in each of orientations corresponding to said overlapping area using the processing unit; a third step for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined in the second step exceeds a predetermined angle value using the processing unit; a fourth step for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously using the processing unit; a fifth step for obtaining for each group representative values of the coordinates of the respective pixels in the group using the processing unit; a sixth step for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group using the processing unit; and a seventh step for obtaining a representative value of the orientations of all of the pixels in each group using the processing unit.

Claim 53

A method for detecting a position of a corner from a contour in a binary contour image implemented by a central processing unit accessing a storage memory unit comprising: a first step for counting the numbers of pixels each having a first predetermined value and located in each of a first plurality of sectorial areas around each pixel having the first predetermined value and located at the center of each of a plurality of local areas, and counting the numbers of pixels each having the first predetermined value and located in each of a second plurality of sectorial areas around said each pixel having the first predetermined value and located at the center of each of the plurality of local areas, where the locations of the second plurality of sectorial areas are different from the locations of the first plurality of sectorial areas, wherein the pixels are stored in the storage memory unit; a second step for obtaining two overlapping areas in each of which one of the first plurality of sectorial areas and one of the second plurality of sectorial areas are overlapped, where the number of pixels located in said one of the first plurality of sectorial areas is greater than a second predetermined value, and the number of pixels located in said one of the second plurality of sectorial areas is greater than the second predetermined value, respectively: and for determining that a local line segment exists in each of orientations corresponding to said overlapping area using the processing unit; a third step for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined in the second step exceeds a predetermined angle value using the processing unit; a fourth step for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously using the processing unit; a fifth step for obtaining for each group representative values of the coordinates of the respective pixels in the group using the processing unit; a sixth step for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group using the processing unit; and a seventh step for obtaining a representative value of the orientations of all of the pixels in each group using the processing unit.

Claim 54

A method for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for obtaining a difference between the number of pixels located in each orientation and a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the central processing unit; a third step for determining that a local line segment exists in a certain orientation when the difference for the orientation is greater than a second predetermined value using the processing unit; a fourth step for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined in the second and third steps exceeds a predetermined angle value using the processing unit; a fifth step for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously using the processing unit; a sixth step for obtaining for each group representative values of the coordinates of the respective pixels in the group using the processing unit; a seventh step for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group using the processing unit; and an eighth step for obtaining a representative value of the orientations of all of the pixels in each group using the processing unit.

Claim 55

A method for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in a plurality of orientations around each of a plurality of pixels respectively located at the centers of a plurality of local areas and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for obtaining a difference between the number of pixels located in each orientation and a sum of the numbers of pixels in orientations adjacent to said each orientation on both sides thereof using the central processing unit; a third step for determining that a local line segment exists in a certain orientation when the difference for the orientation is greater than a second predetermined value using the processing unit; a fourth step for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined in the second and third steps exceeds a predetermined angle value using the processing unit; a fifth step for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously using the processing unit; a sixth step for obtaining for each group representative values of the coordinates of the respective pixels in the group using the processing unit; a seventh step for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group using the processing unit; and an eighth step for obtaining a representative value of the orientations of all of the pixels in each group using the processing unit.

Claim 57

A method for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in each of a plurality of sectorial areas around each of a plurality of pixels respectively located at the centers of a plurality of local areas--and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for obtaining a difference between the number of pixels located in each sectorial area and a sum of the numbers of pixels in sectorial areas adjacent to said each sectorial area on both sides thereof using the processing unit; a third step for determining that a local line segment exists in an orientation corresponding to a sectorial area when the difference for the sectorial area is greater than a second predetermined value using the processing unit; a fourth step for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined in the second and third steps exceeds a predetermined angle value using the processing unit; a fifth step for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously using the processing unit; a sixth step for obtaining for each group representative values of the coordinates of the respective pixels in the group using the processing unit; a seventh step for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group using the processing unit; and an eighth step for obtaining a representative value of the orientations of all of the pixels in each group using the processing unit.

Claim 58

A method for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for obtaining the numbers of pixels each having a first predetermined value and located in each of a plurality of sectorial areas around each of a plurality of pixels respectively located at the centers of a plurality of local areas--and each having said first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for obtaining a difference between the number of pixels located in each sectorial area and a sum of the numbers of pixels in sectorial areas adjacent to said each sectorial area on both sides thereof using the processing unit; a third step for determining that a local line segment exists in an orientation corresponding to a sectorial area when the difference for the sectorial area is greater than a second predetermined value using the processing unit; a fourth step for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined in the second and third steps exceeds a predetermined angle value using the processing unit; a fifth step for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously using the processing unit; a sixth step for obtaining for each group representative values of the coordinates of the respective pixels in the group using the processing unit; a seventh step for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group using the processing unit; and an eighth step for obtaining a representative value of the orientations of all of the pixels in each group using the processing unit.

Claim 59

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for counting the numbers of pixels having a first predetermined value and located in a plurality of sectorial areas which are arranged around each of a plurality of pixels located in the binary contour image and having the first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for determining for each of the plurality of pixels located in the binary contour image and having the first predetermined value, that a local line segment exists in an orientation, corresponding to one of the sectorial areas, from said each of the plurality of pixels, when the number of pixels located in the sectorial area is greater than a second predetermined value using the processing unit; a third step for determining for each of the plurality of pixels located in the binary contour image and having the first predetermined value, that first and second local line segments which are determined to exist in the second step constitute a straight local line segment passing through said each of the plurality of pixels when the orientations of said first and second local line segments differ by 180° from each other using the processing unit; a fourth step for determining for each of the plurality of pixels located in the binary contour image and having the first predetermined value, that third and fourth local line segments constitute a nearly-straight local line segment corresponding to the straight local line segment obtained in the third step when the orientation of the third local line segment is within a predetermined range of azimuth from the orientation of one of the said first and second local line segments constituting the straight local line segment determined in the third step, the orientation of the fourth local line segment is within a predetermined range of azimuth from the orientation of the other of said first and second local line segments, and the difference between the orientations of the above third and fourth local line segments is not equal to 180° using the processing unit; and a fifth step for determining a series of pixels as constituents of a candidate of a line segment when the pixels in the series are contiguously arrayed, at least one of the pixels in the series is the pixel through which the straight local line segment is determined in the third step to pass, the respective orientation of at least one straight local line segment which is determined to pass through said at least one of the pixels in the series is the same, and a nearly-straight local line segment, corresponding to said straight local line segment which is determined to exist in the third step for one of said at least one of the pixels, is determined in the fourth step for each of the pixels other than said at least one pixel in the series using the processing unit.

Claim 60

A method for detecting a line segment from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for counting the numbers of pixels having a first predetermined value and located in a plurality of sectorial areas which are arranged around each of a plurality of pixels located in the binary contour image and having the first predetermined value, wherein the pixels are stored in the storage memory unit; a second step for determining for each of the plurality of pixels located in the binary contour image and having the first predetermined value, that a local line segment exists in an orientation, corresponding to one of the sectorial areas, from said each of the plurality of pixels, when the number of pixels located in the sectorial area is greater than a second predetermined value using the processing unit; a third step for determining for each of the plurality of pixels located in the binary contour image and having the first predetermined value, that first and second local line segments which are determined to exist in the second step constitute a straight local line segment passing through said each of the plurality of pixels when the orientations of said first and second local line segments differ by 180° from each other using the processing unit; a fourth step for determining for each of the plurality of pixels located in the binary contour image and having the first predetermined value, that third and fourth local line segments constitute a nearly-straight local line segment corresponding to the straight local line segment obtained in the third step when the orientation of the third local line segment is within a predetermined range of azimuth from the orientation of one of the said first and second local line segments constituting the straight local line segment determined in the third step, the orientation of the fourth local line segment is within a predetermined range of azimuth from the orientation of the other of said first and second local line segments, and the difference between the orientations of the above third and fourth local line segments is not equal to 180° using the processing unit; and a fifth step for determining a series of pixels as constituents of a candidate of a line segment when the pixels in the series are contiguously arrayed, at least one of the pixels in the series is the pixel through which the straight local line segment is determined in the third step to pass, the respective orientation of at least one straight local line segment which is determined to pass through said at least one of the pixels in the series is the same, and a nearly-straight local line segment, corresponding to said straight local line segment which is determined to exist in the third step for one of said at least one of the pixels, is determined in the fourth step for each of the pixels other than said at least one pixel in the series using the processing unit.

Claim 62

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the number of pixels of the contour points existing in each of a plurality of orientations around a pixel of the contour point in the local area using a processing unit; filter means for obtaining a difference between the number of pixels of the contour points located in said each of the plurality of orientations, and a sum of the numbers of pixels of the contour points located on both sides of said each orientation; and local line segment orientation determining means for obtaining an orientation in which the difference is greater than a predetermined number, as an orientation in which a line segment exists.

Claim 63

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the number of pixels of the contour points existing in each of a plurality of orientations around a pixel of the contour point in the local area using a processing unit; filter means for obtaining a difference between the number of pixels of the contour points located in said each of the plurality of orientations, and a sum of the numbers of pixels of the contour points located on both sides of said each orientation; and local line segment orientation determining means for obtaining an orientation in which the difference is greater than a predetermined number, as an orientation in which a line segment exists.

Claim 64

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including a storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the number of pixels of the contour points existing in each of a plurality of orientations around a pixel of the contour point, located at the center of the local area using the processing unit; filter means for obtaining a difference between the number of pixels of the contour points located in said each of the plurality of orientations, and a sum of the numbers of pixels of the contour points located on both sides of said each orientation; and local line segment orientation determining means for obtaining an orientation in which the difference is greater than a predetermined number, as an orientation in which a line segment exists.

Claim 65

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including a storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the number of pixels of the contour points existing in each of a plurality of orientations around a pixel of the contour point, located at the center of the local area using the processing unit; filter means for obtaining a difference between the number of pixels of the contour points located in said each of the plurality of orientations, and a sum of the numbers of pixels of the contour points located on both sides of said each orientation; and local line segment orientation determining means for obtaining an orientation in which the difference is greater than a predetermined number, as an orientation in which a line segment exists.

Claim 66

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a first plurality of sectorial areas around the center of the local area, and obtaining the numbers of pixels of the contour points located in each of a second plurality of sectorial areas around the center of the local area, where the locations of the second plurality of sectorial areas are different from the locations of the first plurality of sectorial areas, using the processing unit; filter means for obtaining for each of the first and second patterns a difference between the number of pixels of the contour points located in each of the plurality of sectorial areas and a sum of the numbers of pixels of the contour points in orientations adjacent to said each orientation on both sides thereof; in-pattern orientation determining means for obtaining for each of the first and second patterns an orientation corresponding to one of the areas for which the difference is greater than a predetermined value; and local line segment orientation determining means for obtaining two overlapping areas in each of which one of the first plurality of sectorial areas and one of the second plurality of sectorial areas are overlapped, where the number of pixels located in said one of the first plurality of sectorial areas is greater than a second predetermined value, and the number of pixels located in said one of the second plurality of sectorial areas is greater than the second predetermined value, respectively; and for determining that a local line segment exists in orientations corresponding to said overlapping areas.

Claim 67

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a first plurality of sectorial areas around the center of the local area, and obtaining the numbers of pixels of the contour points located in each of a second plurality of sectorial areas around the center of the local area, where the locations of the second plurality of sectorial areas are different from the locations of the first plurality of sectorial areas, using the processing unit; filter means for obtaining for each of the first and second patterns a difference between the number of pixels of the contour points located in each of the plurality of sectorial areas and a sum of the numbers of pixels of the contour points in orientations adjacent to said each orientation on both sides thereof; in-pattern orientation determining means for obtaining for each of the first and second patterns an orientation corresponding to one of the areas for which the difference is greater than a predetermined value; and local line segment orientation determining means for obtaining two overlapping areas in each of which one of the first plurality of sectorial areas and one of the second plurality of sectorial areas are overlapped, where the number of pixels located in said one of the first plurality of sectorial areas is greater than a second predetermined value, and the number of pixels located in said one of the second plurality of sectorial areas is greater than the second predetermined value, respectively; and for determining that a local line segment exists in orientations corresponding to said overlapping areas.

Claim 68

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of orientations around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas using the processing unit; local line segment orientation detecting means for determining that a local line segment exists in a certain orientation when the number of pixels located in the orientation is greater than a predetermined value; local line segment detecting means for determining that a straight local line segment passing through said each of the plurality of pixels exists in the local area when two local line segments are determined to exist by the local line segment orientation detecting means, and the orientations of the two local line segments differ by 180° from each other; and line segment candidate detecting means for determining that a group of contiguously arrayed pixels constitute a candidate of a straight local line segment when line segments in the same orientation pass through the contiguously arrayed pixels in the local area.

Claim 69

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of orientations around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas using the processing unit; local line segment orientation detecting means for determining that a local line segment exists in a certain orientation when the number of pixels located in the orientation is greater than a predetermined value; local line segment detecting means for determining that a straight local line segment passing through said each of the plurality of pixels exists in the local area when two local line segments are determined to exist by the local line segment orientation detecting means, and the orientations of the two local line segments differ by 180° from each other; and line segment candidate detecting means for determining that a group of contiguously arrayed pixels constitute a candidate of a straight local line segment when line segments in the same orientation pass through the contiguously arrayed pixels in the local area.

Claim 70

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of sectorial areas around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas using the processing unit; local line segment orientation detecting means for determining that a local line segment exists in an orientation corresponding to one of the sectorial areas when the number of pixels located in the sectorial area is greater than a predetermined value; local line segment detecting means for determining that a straight local line segment passing through said each of the plurality of pixels exists in the local area when two local line segments are determined to exist by the local line segment orientation detecting means, and the orientations of the two local line segments differ by 180° from each other; and line segment candidate detecting means for determining that a group of contiguously arrayed pixels constitute a candidate of a straight local line segment when line segments in the same orientation pass through the contiguously arrayed pixels in the local area.

Claim 71

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of sectorial areas around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas using the processing unit; local line segment orientation detecting means for determining that a local line segment exists in an orientation corresponding to one of the sectorial areas when the number of pixels located in the sectorial area is greater than a predetermined value; local line segment detecting means for determining that a straight local line segment passing through said each of the plurality of pixels exists in the local area when two local line segments are determined to exist by the local line segment orientation detecting means, and the orientations of the two local line segments differ by 180° from each other; and line segment candidate detecting means for determining that a group of contiguously arrayed pixels constitute a candidate of a straight local line segment when line segments in the same orientation pass through the contiguously arrayed pixels in the local area.

Claim 72

An apparatus for determining an orientation of local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels each having a first predetermined value and located in each of a first plurality of sectorial areas around each pixel having the first predetermined value and located at the center of each of a plurality of local areas, and obtaining the numbers of pixels each having the first predetermined value located in each of a second plurality of sectorial areas around said each pixel having the first predetermined value and located at the center of each of the plurality of local areas, where the locations of the second plurality of sectorial areas are different from the locations of the first plurality of sectorial-areas using the processing unit: local line segment orientation determining means for obtaining two overlapping areas in each of which one of the first plurality of sectorial areas and one of the second plurality of sectorial areas are overlapped, where the number of pixels located in said one of the first plurality of sectorial areas is greater than a second predetermined value, and the number of pixels located in said one of the second plurality of sectorial areas is greater than the second predetermined value, respectively; and for determining that a local line segment exists in each of orientations corresponding to said overlapping areas; local line segment detecting means for determining that a straight local line segment passing through said each pixel exists in the local area when two local line segments are determined to exist by the local line segment orientation detecting means, and the orientations of the two local line segments differ by 180° from each other; and line segment candidate detecting means for determining that a group of contiguously arrayed pixels constitute a candidate of a straight local line segment when line segments in the same orientation pass through the contiguously arrayed pixels in the local area.

Claim 73

An apparatus for determining an orientation of local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels each having a first predetermined value and located in each of a first plurality of sectorial areas around each pixel having the first predetermined value and located at the center of each of a plurality of local areas, and obtaining the numbers of pixels each having the first predetermined value located in each of a second plurality of sectorial areas around said each pixel having the first predetermined value and located at the center of each of the plurality of local areas, where the locations of the second plurality of sectorial areas are different from the locations of the first plurality of sectorial-areas using the processing unit: local line segment orientation determining means for obtaining two overlapping areas in each of which one of the first plurality of sectorial areas and one of the second plurality of sectorial areas are overlapped, where the number of pixels located in said one of the first plurality of sectorial areas is greater than a second predetermined value, and the number of pixels located in said one of the second plurality of sectorial areas is greater than the second predetermined value, respectively; and for determining that a local line segment exists in each of orientations corresponding to said overlapping areas; local line segment detecting means for determining that a straight local line segment passing through said each pixel exists in the local area when two local line segments are determined to exist by the local line segment orientation detecting means, and the orientations of the two local line segments differ by 180° from each other; and line segment candidate detecting means for determining that a group of contiguously arrayed pixels constitute a candidate of a straight local line segment when line segments in the same orientation pass through the contiguously arrayed pixels in the local area.

Claim 74

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of orientations around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas using the processing unit; filter means for obtaining a difference between the number of pixels of the contour points located in said each of the plurality of orientations, and a sum of the numbers of pixels of the contour points located on both sides of said each orientation; local line segment orientation detecting means for determining that a local line segment exists in a certain orientation when the difference for the orientation is greater than a predetermined value; local line segment detecting means for determining, when first and second local line segments are determined to exist by the local line segment orientation detecting means, and the orientations of the first and second local line segments differ by 180° from each other, that a straight local line segment passing through said each of the plurality of pixels exists in the local area; and line segment candidate detecting means for determining that a group of contiguously arrayed pixels constitute a candidate of a straight local line segment when line segments in the same orientation pass through the contiguously arrayed pixels in the local area.

Claim 75

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of orientations around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas using the processing unit; filter means for obtaining a difference between the number of pixels of the contour points located in said each of the plurality of orientations, and a sum of the numbers of pixels of the contour points located on both sides of said each orientation; local line segment orientation detecting means for determining that a local line segment exists in a certain orientation when the difference for the orientation is greater than a predetermined value; local line segment detecting means for determining, when first and second local line segments are determined to exist by the local line segment orientation detecting means, and the orientations of the first and second local line segments differ by 180° from each other, that a straight local line segment passing through said each of the plurality of pixels exists in the local area; and line segment candidate detecting means for determining that a group of contiguously arrayed pixels constitute a candidate of a straight local line segment when line segments in the same orientation pass through the contiguously arrayed pixels in the local area.

Claim 76

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of sectorial areas around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas; filter means for obtaining a difference between the number of pixels of the contour points located in said each of the plurality of sectorial areas, and a sum of the numbers of pixels of the contour points located in sectorial areas on both sides of said each sectorial area; local line segment orientation detecting means for determining that a local line segment exists in an orientation corresponding to a sectorial area when the difference for the sectorial area is greater than a predetermined value; local line segment detecting means for determining that a straight local line segment passing through said each of the plurality of pixels exists in the local area, when line segments are determined to exist by the local line segment orientation detecting means, and the orientations of the local line segments differ by 180° from each other; and line segment candidate detecting means for determining that a group of contiguously arrayed pixels constitute a candidate of a straight local line segment when line segments in the same orientation pass through the contiguously arrayed pixels in the local area.

Claim 77

An apparatus for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of sectorial areas around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas; filter means for obtaining a difference between the number of pixels of the contour points located in said each of the plurality of sectorial areas, and a sum of the numbers of pixels of the contour points located in sectorial areas on both sides of said each sectorial area; local line segment orientation detecting means for determining that a local line segment exists in an orientation corresponding to a sectorial area when the difference for the sectorial area is greater than a predetermined value; local line segment detecting means for determining that a straight local line segment passing through said each of the plurality of pixels exists in the local area, when line segments are determined to exist by the local line segment orientation detecting means, and the orientations of the local line segments differ by 180° from each other; and line segment candidate detecting means for determining that a group of contiguously arrayed pixels constitute a candidate of a straight local line segment when line segments in the same orientation pass through the contiguously arrayed pixels in the local area.

Claim 78

An apparatus for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of orientations around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas; local line segment orientation detecting means for determining that a local line segment exists in a certain orientation when the number of pixels for the orientation is greater than a predetermined value; near-corner-point detecting means for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined by the local line segment orientation determining means exceeds a predetermined angle value; near-corner-point series detecting means for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously; corner representative value determining means for obtaining for each group representative values of the coordinates of the respective pixels in the group; near-corner-point corner-orientation determining means for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group; and corner-orientation representative value determining means for obtaining a representative value of the orientations of all of the pixels in each group.

Claim 79

An apparatus for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of orientations around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas; local line segment orientation detecting means for determining that a local line segment exists in a certain orientation when the number of pixels for the orientation is greater than a predetermined value; near-corner-point detecting means for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined by the local line segment orientation determining means exceeds a predetermined angle value; near-corner-point series detecting means for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously; corner representative value determining means for obtaining for each group representative values of the coordinates of the respective pixels in the group; near-corner-point corner-orientation determining means for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group; and corner-orientation representative value determining means for obtaining a representative value of the orientations of all of the pixels in each group.

Claim 80

An apparatus for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of sectorial areas around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas using the processing unit; local line segment orientation detecting means for determining that a local line segment exists in an orientation corresponding to a sectorial area when the number of pixels for the sectorial area is greater than a predetermined value; near-corner-point detecting means for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined by the local line segment orientation determining means exceeds a predetermined angle value; near-corner-point series detecting means for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously; corner representative value determining means for obtaining for each group representative values of the coordinates of the respective pixels in the group; near-corner-point corner-orientation determining means for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group; and corner-orientation representative value determining means for obtaining a representative value of the orientations of all of the pixels in each group.

Claim 81

An apparatus for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of sectorial areas around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas using the processing unit; local line segment orientation detecting means for determining that a local line segment exists in an orientation corresponding to a sectorial area when the number of pixels for the sectorial area is greater than a predetermined value; near-corner-point detecting means for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined by the local line segment orientation determining means exceeds a predetermined angle value; near-corner-point series detecting means for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously; corner representative value determining means for obtaining for each group representative values of the coordinates of the respective pixels in the group; near-corner-point corner-orientation determining means for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group; and corner-orientation representative value determining means for obtaining a representative value of the orientations of all of the pixels in each group.

Claim 82

An apparatus for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels each having a first predetermined value and located in each of a first plurality of sectorial areas around each pixel having the first predetermined value and located at the center of each of a plurality of local areas, and obtaining the numbers of pixels each having the first predetermined value and located in each of the second plurality of sectorial areas around said each pixel having the first predetermined value and located at the center of each of the plurality of local areas, where the locations of the second plurality of sectorial areas are different from the locations of the first plurality of sectorial areas using the processing unit; local line segment orientation determining means for obtaining two overlapping areas in each of which one of the first plurality of sectorial areas and one of the second plurality of sectorial areas are overlapped, where the number of pixels located in said one of the first plurality of sectorial areas is greater than a second predetermined value, and the number of pixels located in said one of the second plurality of sectorial areas is greater than the second predetermined value, respectively; and for determining that a local line segment exists in each of orientations corresponding to said overlapping areas; near-corner-point detecting means for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined by the local line segment orientation determining means exceeds a predetermined angle value; near-corner-point series detecting means for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously: corner representative value determining means for obtaining for each group representative values of the coordinates of the respective pixels in the group; near-corner-point corner-orientation determining means for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group; and corner-orientation representative value determining means for obtaining a representative value of the orientations of all of the pixels in each group.

Claim 83

An apparatus for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels each having a first predetermined value and located in each of a first plurality of sectorial areas around each pixel having the first predetermined value and located at the center of each of a plurality of local areas, and obtaining the numbers of pixels each having the first predetermined value and located in each of the second plurality of sectorial areas around said each pixel having the first predetermined value and located at the center of each of the plurality of local areas, where the locations of the second plurality of sectorial areas are different from the locations of the first plurality of sectorial areas using the processing unit; local line segment orientation determining means for obtaining two overlapping areas in each of which one of the first plurality of sectorial areas and one of the second plurality of sectorial areas are overlapped, where the number of pixels located in said one of the first plurality of sectorial areas is greater than a second predetermined value, and the number of pixels located in said one of the second plurality of sectorial areas is greater than the second predetermined value, respectively; and for determining that a local line segment exists in each of orientations corresponding to said overlapping areas; near-corner-point detecting means for determining in each of the plurality of local areas that the pixel located at the center of the local area is a near-corner point when an absolute value of a difference between 180° and a difference between the orientations of the two local line segments determined by the local line segment orientation determining means exceeds a predetermined angle value; near-corner-point series detecting means for obtaining a group of pixels which are determined as the near-corner point, and are arrayed contiguously: corner representative value determining means for obtaining for each group representative values of the coordinates of the respective pixels in the group; near-corner-point corner-orientation determining means for obtaining for each group as a corner orientation of the near-corner points a mean orientation of the orientations of the two local line segments in the local area containing at the center of the local area each pixel in the group; and corner-orientation representative value determining means for obtaining a representative value of the orientations of all of the pixels in each group.

Claim 84

An apparatus for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of orientations around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas using the central processing unit; filter means for obtaining a difference between the number of pixels of the contour points located in said each of the plurality of orientations, and a sum of the number of pixels of the contour points in orientations on both sides of said each orientation; local line segment orientation detecting means for determining that a local line segment exists in a certain orientation when the difference for the orientation is greater than a predetermined value; local line segment detecting means for determining that a straight local line segment passing through said each of the plurality of pixels exists in the local area, when line segments are determined to exist by the local line segment orientation detecting means, and the orientations of the local line segments differ by 180° from each other; and line segment candidate detecting means for determining that a group of contiguously arrayed pixels constitute a candidate of a straight local line segment when line segments in the same orientation pass through the contiguously arrayed pixels in the local area.

Claim 85

An apparatus for detecting a position of a corner from a contour in a binary contour image implemented by a processing unit accessing a storage memory unit comprising: contour image information holding means, including the storage memory unit, for holding information indicating at least coordinates of contour points of the binary contour image; pixel number counting means, including the processing unit, for obtaining the numbers of pixels of the contour points located in each of a plurality of orientations around each of a plurality of pixels of the contour points respectively located at the centers of a plurality of local areas using the central processing unit; filter means for obtaining a difference between the number of pixels of the contour points located in said each of the plurality of orientations, and a sum of the number of pixels of the contour points in orientations on both sides of said each orientation; local line segment orientation detecting means for determining that a local line segment exists in a certain orientation when the difference for the orientation is greater than a predetermined value; local line segment detecting means for determining that a straight local line segment passing through said each of the plurality of pixels exists in the local area, when line segments are determined to exist by the local line segment orientation detecting means, and the orientations of the local line segments differ by 180° from each other; and line segment candidate detecting means for determining that a group of contiguously arrayed pixels constitute a candidate of a straight local line segment when line segments in the same orientation pass through the contiguously arrayed pixels in the local area.

Claim 86

A method for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a central processing unit accessing a storage memory unit comprising the steps of: obtaining the numbers of pixels located in a plurality of orientations around one of pixels located in the local area and having a predetermined value, wherein the pixels are stored in the storage memory unit; obtaining a sum of the numbers of pixels in orientations adjacent to each of the plurality of orientations on both sides thereof; obtaining a difference between the number of pixels located in said each orientation and said sum using the processing unit; and determining that local line segments exist in two orientations among said plurality of orientations when said difference obtained in the third step is the largest and the second largest in said two orientations, respectively, using the processing unit.

Claim 87

A method for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a central processing unit accessing a storage memory unit comprising the steps of: obtaining the numbers of pixels located in a plurality of orientations around one of pixels located in the local area and having a predetermined value, wherein the pixels are stored in the storage memory unit; obtaining a sum of the numbers of pixels in orientations adjacent to each of the plurality of orientations on both sides thereof; obtaining a difference between the number of pixels located in said each orientation and said sum using the processing unit; and determining that local line segments exist in two orientations among said plurality of orientations when said difference obtained in the third step is the largest and the second largest in said two orientations, respectively, using the processing unit.

Claim 88

A method for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for obtaining the numbers of pixels each located in a plurality of orientations around one of pixels located in the local area, wherein the pixels are stored in the storage memory unit; and a second step for determining that a local line segment exists in an orientation in which the number of pixels located in the orientation is greater than predetermined value, wherein the pixels are stored in the storage memory unit.

Claim 89

A method for determining an orientation of a local line segment in a contour in a local area of a binary contour image implemented by a processing unit accessing a storage memory unit comprising: a first step for obtaining the numbers of pixels each located in a plurality of orientations around one of pixels located in the local area, wherein the pixels are stored in the storage memory unit; and a second step for determining that a local line segment exists in an orientation in which the number of pixels located in the orientation is greater than predetermined value, wherein the pixels are stored in the storage memory unit.