Method of detecting the position of an object pattern in an image

Claim 1

A method of detecting the position of an object pattern in an image, comprising the steps of: (a) preparing two or more reference patterns which have a foreground pattern and a background, said foreground pattern and background being composed of one or more pixels each having a value of 1, 0 or -1 regarding the brightness wherein the total of said values is zero, the shape obtained from said foreground patterns when said reference patterns are arranged in a predetermined geometrical or positional relationship corresponding to said object pattern, the brightness value of each pixel of said foreground pattern being different from that of each pixel of said background, a portion of each of said reference patterns being designated as a specific portion, such that pixels having a value of 0 are not positioned between pixels having a value of 1 and pixels having a value of -1; (b) storing said positional relationship; (c) dividing said image into a plurality of sections; (d) selecting arbitrarily an area having two or more of said sections, the shape of said area corresponding to that of said reference pattern; (e) obtaining brightness data from each of said sections; (f) obtaining a sum of products of the brightness value of each pixel of both said reference pattern and other reference patterns and the brightness data of each section corresponding to the pixel; (g) moving said area to another position in said image; (h) repeating steps (e) to (g); (i) selecting two or more portions from which the sum having an extreme value or a value adjacent to said extreme value is obtained, for both said reference pattern and other reference patterns; (j) obtaining the position in each of said selected portions which corresponds to said specific part or said other specific part; (k) obtaining the positional relationships in each pair of said obtained positions; (l) obtaining the pair having the positional relationship which is closest to said stored positional relationship; and (m) deciding that the area which corresponds to said obtained pair is the one containing said object pattern.

Claim 2

A method of detecting the position of an object pattern in an image, comprising the steps of: (a) preparing two or more reference patterns which have a foreground pattern and a background, said foreground pattern and background being composed of one or more pixels each having a value of 1, 0 or -1 regarding the brightness wherein the total of said values is zero, the shape obtained from said foreground patterns when said reference patterns are arranged in a predetermined geometrical or positional relationship corresponding to said object pattern, the brightness value of each pixel of said foreground pattern being different from that of each pixel of said background, a portion of each of said reference patterns being designated as a specific portion, such that pixels having a value of 0 are not positioned between pixels having a value of 1 and pixels having a value of -1; (b) storing said positional relationship; (c) dividing said image into a plurality of sections; (d) selecting arbitrarily an area having two or more of said sections, the shape of said area corresponding to that of said reference pattern; (e) obtaining brightness data from each of said sections; (f) obtaining a sum of products of the brightness value of each pixel of both said reference pattern and other reference patterns and the brightness data of each section corresponding to the pixel; (g) moving said area to another position in said image; (h) repeating steps (e) to (g); (i) selecting two or more portions from which the sum having an extreme value or a value adjacent to said extreme value is obtained, for both said reference pattern and other reference patterns; (j) obtaining the position in each of said selected portions which corresponds to said specific part or said other specific part; (k) obtaining the positional relationships in each pair of said obtained positions; (l) obtaining the pair having the positional relationship which is closest to said stored positional relationship; and (m) deciding that the area which corresponds to said obtained pair is the one containing said object pattern.