Pattern matching method with pixel vectors

A method for matching a pattern with one of a plurality of standard samples comprising the steps of:

• representing a recognition image captured from a recognition-objected sample by an m.times.n matrix of binary pixels forming a binary image, where each of m and n is an integer;
• forming a plurality of M pixel trains v.sub.i by choosing, from said m.times.n matrix of binary pixels, a consecutive sequence of binary pixels according to prescribed rules for each pixel train v.sub.i, where i is an index having integer values in a range between 1 and a predetermined integer M;
• choosing a predetermined subset of said pixel trains v.sub.i of said binary pixels;
• matching each of said chosen subset of pixel trains v.sub.i to reference pixel trains G.sub.ki respectively corresponding thereto for each of a plurality of N standard samples, where k is an index having integer values between 1 and a predetermined integer N;
• wherein said reference pixel trains G.sub.ki are formed by obtaining a cluster of pixel trains g.sub.ki from N m.times.n pixel matrices each representing a respective standard image for a standard sample k, and by generating multiplex pixel trains g.sub.ki ' by performing a predetermined systematic modification of pixels in said pixel trains g.sub.ki to form, together with said pixel trains g.sub.ki, said reference pixel trains G.sub.ki ;
• maintaining a score for each standard sample k of said N standard samples in accordance with a number of matches between said reference pixel trains G.sub.ki thereof and the corresponding chosen subset of pixel trains v.sub.i, by:
• i) adding a predetermined amount to the score of any standard sample k of said N standard samples when a particular pixel train G.sub.ki thereof matches a corresponding one of said chosen subset of pixel trains v.sub.i, and
• ii) subtracting a predetermined amount from the score of any standard sample k of said N standard samples when a particular pixel train G.sub.ki thereof never matches a corresponding one of said chosen subset of pixel trains v.sub.i,
• and
• identifying a particular one of said N standard sample as matching and representing said recognition-objected sample when said particular standard sample has a maximum score of said scores maintained for said standard samples.

In a method for matching a recognition object with one of a plurality of N standard patterns where N is an integer, implemented on an apparatus including means for capturing the recognition object, binarizing and normalizing the recognition object and forming a matrix of binary pixels representing a binary image of the recognition object, improvement comprising:

• generating input signals corresponding to a plurality of input pixel trains v.sub.i, said input signals for each input pixel train representing a respective consecutive sequence of binary pixels selected in accordance with prescribed rules from said matrix, where i is an index having integer values greater than 1,
• producing reference signals corresponding to reference pixel trains G.sub.ki of a kth one of said plurality of standard patterns, where k is an integer between 1 and N, said reference pixel trains representing sequences of binary pixels from matrices representing binary images of the standard patterns respectively corresponding to said sequences of binary pixels selected from said matrix representing the recognition object, by:
• a) obtaining first signals corresponding to a cluster of pixel trains g.sub.ki from said N pixel matrices each representing a respective standard image for a standard sample k, and
• b) obtaining second signals corresponding to multiplex pixel trains g.sub.ki ' by performing a predetermined systematic modification of said first signals for pixels to form, together with said first signals, said reference signals corresponding to said reference pixel trains G.sub.ki ;
• generating output signals representing matches between said input signals, corresponding to said input pixel trains v.sub.i of the recognition object, and reference signals corresponding to reference pixel trains G.sub.ki
• maintaining a score for each of said plurality of N standard patterns in accordance with a number of matches occurring between said input pixel trains v.sub.i and said reference pixel trains G.sub.ki thereof, and
• providing an output signal identifying a particular one of said standard patterns as matching said recognition object when said particular standard sample has a maximum score of said scores maintained for said N standard patterns.

In an apparatus for matching a recognition object with one of a plurality of N standard patterns including means for capturing the recognition object, where N is an integer, and for binarizing and normalizing the recognition object and forming an m.times.n matrix of binary pixels representing a binary image of the recognition object, the improvement comprising:

• a first circuit having an input for receiving input signals representing a plurality of input pixel trains v.sub.i, each input pixel train representing a respective consecutive sequence of binary pixels selected in accordance with prescribed rules from said m.times.n matrix, where i is an index having integer values greater than 1,
• said first circuit having an output for outputting signals representing matches between each input pixel train v.sub.i of the recognition object, representing a sequence of pixels from said m.times.n matrix, and corresponding reference pixel trains G.sub.ki of a kth one of said plurality of standard patterns, representing respectively corresponding sequences of binary pixels from matrices representing binary images of the standard patterns, where k is an integer between 1 and N,
• wherein said reference pixel trains G.sub.ki comprise:
• a) a cluster of first pixel trains g.sub.ki, from N m.times.n matrices each representing a respective kth binary image, for a kth standard pattern, and
• b) multiplex pixel trains g.sub.ki ', generated by predetermined systematic modification of constituent pixels in said first pixel trains g.sub.ki,
• a second circuit for maintaining a score for each of said plurality of N standard patterns in accordance with a number of matches between said input pixel trains v.sub.i and said reference pixel trains G.sub.ki thereof, and
• a selector for identifying a particular one of said standard patterns as matching and representing said recognition object when said particular standard sample has a maximum score of said scores maintained for said N standard patterns.