Pattern detection method

Claim 1

A method of pattern detection comprising the steps of: obtaining an image of an object; converting the image obtained into two-dimensional image data P(X, Y) at points (X, Y), wherein X and Y denote coordinates existing along two directions perpendicular to one another; setting operation reference points C s (X m , Y n ) in two dimensions spaced from each other by a step size which is smaller than a size of the image of the object, wherein X m and Y n denote m-th and n-th coordinates existing along two directions and m and n denote integral numbers; providing a two-dimensional template having a size smaller than the image of the object and having weights T(x i , y i ) at a plurality of points (x i , y i ) wherein x i and y i denote x and y coordinates of an i-th point and i denotes an integral number; setting a position reference point of the template T(x i , y i ) at each of the operation reference points C s (X m , Y n ); calculating a weighted sum of the image data P(X, Y) by using the template T(x i , y i ) for each of the operation reference points C s (X m , Y n ); determining the operation reference points C s (X m , Y n ) as being candidate points when the weighted sum thereof is larger than a predetermined value; grouping the candidate points into candidate groups comprising a plurality of adjacent candidate points, wherein the candidate groups sufficiently define a representative contour of the object; and determining a position of the object based on positions of the candidate groups.

Claim 2

A method of pattern detection comprising the steps of: obtaining an image of an object; converting the image obtained into two-dimensional image data P(X, Y) at points (X, Y), wherein X and Y denote coordinates existing along two directions perpendicular to one another; setting operation reference points C s (X m , Y n ) in two dimensions spaced from each other by a step size which is smaller than a size of the image of the object, wherein X m and Y n denote m-th and n-th coordinates existing along two directions and m and n denote integral numbers; providing a two-dimensional template having a size smaller than the image of the object and having weights T(x i , y i ) at a plurality of points (x i , y i ) wherein x i and y i denote x and y coordinates of an i-th point and i denotes an integral number; setting a position reference point of the template T(x i , y i ) at each of the operation reference points C s (X m , Y n ); calculating a weighted sum of the image data P(X, Y) by using the template T(x i , y i ) for each of the operation reference points C s (X m , Y n ); determining the operation reference points C s (X m , Y n ) as being candidate points when the weighted sum thereof is larger than a predetermined value; grouping the candidate points into candidate groups comprising a plurality of adjacent candidate points, wherein the candidate groups sufficiently define a representative contour of the object; and determining a position of the object based on positions of the candidate groups.