Feature extraction technique for use in a pattern recognition system

Claim 1

The method of creating an output feature vector array of height P and width Q representing an input pattern, comprising the steps of: obtaining said input pattern in the form of an input array of height N and width M; forming an intermediate array having a height NP and width MQ; using the information contained in said input array to provide data for said intermediate array; and using the information contained in said intermediate array to provide data for said output feature vector array.

Claim 2

The method of creating an output feature vector array of height P and width Q representing an input pattern, comprising the steps of: obtaining said input pattern in the form of an input array of height N and width M; forming an intermediate array having a height NP and width MQ; using the information contained in said input array to provide data for said intermediate array; and using the information contained in said intermediate array to provide data for said output feature vector array.

Claim 4

A method for extracting features of a pattern consisting of pixel data comprising the steps of: fetching a pattern image containing a plurality of elements; creating a blurred pattern image by applying a transformation to said pattern image comprising the steps of: creating an intermediate array consisting of said elements of said pattern image each written P times vertically and Q times horizontally; and creating an output array containing one or more elements of a feature vector, said output array having horizontal dimension Q and vertical dimension P, said output array consisting of the elements of said intermediate array summed in groups of N vertical elements and M horizontal elements, where N is the height of said pattern image in pixels and M is the width of the pattern image in pixels.

Claim 5

A method for extracting features of a pattern consisting of pixel data comprising the steps of: fetching a pattern image containing a plurality of elements; creating a blurred pattern image by applying a transformation to said pattern image comprising the steps of: creating an intermediate array consisting of said elements of said pattern image each written P times vertically and Q times horizontally; and creating an output array containing one or more elements of a feature vector, said output array having horizontal dimension Q and vertical dimension P, said output array consisting of the elements of said intermediate array summed in groups of N vertical elements and M horizontal elements, where N is the height of said pattern image in pixels and M is the width of the pattern image in pixels.

Claim 6

A method for extracting features of a pattern consisting of pixel data comprising the steps of: fetching a pattern image containing a plurality of elements; creating a blurred pattern image by applying a transformation to said pattern image, comprising the steps of: creating an intermediate array having a first dimension equal to the number of regions into which said pattern image is desired to be divided in said first dimension and having a second dimension equal to the number of pixels of said pattern image in said second dimension; using counters to determine which pixel in said pattern image is to have its value added to which element of said intermediate array; and using counters to determine which element in said intermediate array is to have its value added to which element of an output array containing a feature vector or part of a feature vector.

Claim 7

A method for extracting features of a pattern consisting of pixel data comprising the steps of: fetching a pattern image containing a plurality of elements; creating a blurred pattern image by applying a transformation to said pattern image, comprising the steps of: creating an intermediate array having a first dimension equal to the number of regions into which said pattern image is desired to be divided in said first dimension and having a second dimension equal to the number of pixels of said pattern image in said second dimension; using counters to determine which pixel in said pattern image is to have its value added to which element of said intermediate array; and using counters to determine which element in said intermediate array is to have its value added to which element of an output array containing a feature vector or part of a feature vector.

Claim 8

A method for extracting features of a pattern consisting of pixel data comprising the steps of: fetching a pattern image including a plurality of elements arranged in a plurality of rows of pixels; applying a transformation to said pixels to create a transformed input pattern; and using said transformed input pattern to produce in an output array a feature vector, or part of a feature vector, for pattern recognition; said transformation comprising the steps of: generating first multiples of said pixels in a first expansion of said pattern image; and generating second multiples of said pixels in a second expansion of said pattern; and whereby said step of using said transformed input pattern comprises the steps of summing said first and second multiple pixels in equally sized groups, each of said sums of said first and second multiples of said pixels being a member of said feature vector.

Claim 9

A method for extracting features of a pattern consisting of pixel data comprising the steps of: fetching a pattern image including a plurality of elements arranged in a plurality of rows of pixels; applying a transformation to said pixels to create a transformed input pattern; and using said transformed input pattern to produce in an output array a feature vector, or part of a feature vector, for pattern recognition; said transformation comprising the steps of: generating first multiples of said pixels in a first expansion of said pattern image; and generating second multiples of said pixels in a second expansion of said pattern; and whereby said step of using said transformed input pattern comprises the steps of summing said first and second multiple pixels in equally sized groups, each of said sums of said first and second multiples of said pixels being a member of said feature vector.

Claim 12

A method for extracting features of a pattern consisting of pixel data comprising the steps of: fetching a pattern image including a plurality of elements arranged in a plurality of rows of pixels; applying a transformation to said pixels to produce in an output array a feature vector, or part of a feature vector, for pattern recognition, said output array including a plurality of groups of elements representing corresponding rows of said output array, said transformation comprising the steps of: summing the value of each pixel in a row of said pixels of said pattern image for a first predetermined number of times (Q) into an intermediate accumulator and advancing to the next one of said pixels in said row; transferring the contents of said intermediate accumulator to an element of said output array and restoring said intermediate accumulator with the value of the next element of said output array after each of a second predetermined number of accumulating steps (M); repeating said step of summing and said step of transferring for a third predetermined number of times (N) before advancing to the next group of elements of said output array; and repeating said step of summing and said step of transferring for a fourth predetermined number of times (P) before advancing to the first element of the next row of said pixels, wherein said first predetermined number is equal to the number of elements in a row of said output array; wherein said second predetermined number if equal to the number of pixels in a row of said image pattern; wherein said third predetermined number is equal to the number of rows in said output array; and wherein said fourth predetermined number is equal to the number of rows of said image pattern.

Claim 13

A method for extracting features of a pattern consisting of pixel data comprising the steps of: fetching a pattern image including a plurality of elements arranged in a plurality of rows of pixels; applying a transformation to said pixels to produce in an output array a feature vector, or part of a feature vector, for pattern recognition, said output array including a plurality of groups of elements representing corresponding rows of said output array, said transformation comprising the steps of: summing the value of each pixel in a row of said pixels of said pattern image for a first predetermined number of times (Q) into an intermediate accumulator and advancing to the next one of said pixels in said row; transferring the contents of said intermediate accumulator to an element of said output array and restoring said intermediate accumulator with the value of the next element of said output array after each of a second predetermined number of accumulating steps (M); repeating said step of summing and said step of transferring for a third predetermined number of times (N) before advancing to the next group of elements of said output array; and repeating said step of summing and said step of transferring for a fourth predetermined number of times (P) before advancing to the first element of the next row of said pixels, wherein said first predetermined number is equal to the number of elements in a row of said output array; wherein said second predetermined number if equal to the number of pixels in a row of said image pattern; wherein said third predetermined number is equal to the number of rows in said output array; and wherein said fourth predetermined number is equal to the number of rows of said image pattern.

Claim 14

A method for extracting features of a pattern consisting of pixel data comprising the steps of: fetching a pattern image including a plurality of elements arranged in a plurality of rows of pixels; applying a transformation to said pixels to produce in an output array a feature vector, or part of a feature vector, for pattern recognition, said transformation comprising the steps of: summing the value of each pixel in a row of said pixels of said pattern image for a first predetermined number of time (Q) into an intermediate accumulator and advancing to the next one of said pixels; transferring the contents of said intermediate accumulator to an element of said intermediate array after each of a second predetermined number of summing steps (M); advancing to the next row of said pixels and the next element of said output array when all pixels of a row of pixels is processed; summing the value of each element in a column of said intermediate array for a third predetermined number of times (N) into an output accumulator and advancing to the next element of said intermediate array; transferring the contents of said output accumulator to an element of said output array after each of a fourth predetermined number of summing steps (P); and advancing to the next column of elements of said intermediate array and said elements of said output array when all elements of a column of said intermediate array are processed, wherein said first predetermined number is equal to the number of elements in a row of said output array; wherein said second predetermined number if equal to the number of pixels in a row of said image pattern; wherein said third predetermined number is equal to the number of rows in said output array; and wherein said fourth predetermined number is equal to the number of rows of said image pattern.

Claim 15

A method for extracting features of a pattern consisting of pixel data comprising the steps of: fetching a pattern image including a plurality of elements arranged in a plurality of rows of pixels; applying a transformation to said pixels to produce in an output array a feature vector, or part of a feature vector, for pattern recognition, said transformation comprising the steps of: summing the value of each pixel in a row of said pixels of said pattern image for a first predetermined number of time (Q) into an intermediate accumulator and advancing to the next one of said pixels; transferring the contents of said intermediate accumulator to an element of said intermediate array after each of a second predetermined number of summing steps (M); advancing to the next row of said pixels and the next element of said output array when all pixels of a row of pixels is processed; summing the value of each element in a column of said intermediate array for a third predetermined number of times (N) into an output accumulator and advancing to the next element of said intermediate array; transferring the contents of said output accumulator to an element of said output array after each of a fourth predetermined number of summing steps (P); and advancing to the next column of elements of said intermediate array and said elements of said output array when all elements of a column of said intermediate array are processed, wherein said first predetermined number is equal to the number of elements in a row of said output array; wherein said second predetermined number if equal to the number of pixels in a row of said image pattern; wherein said third predetermined number is equal to the number of rows in said output array; and wherein said fourth predetermined number is equal to the number of rows of said image pattern.

Claim 16

The method as in claims 3, 4, 5, 8 or 9 wherein elements of said output array represent portions of said pattern image which are equally spaced across the width of said pattern image.

Claim 17

The method as in claims 3, 4, 5, 8 or 9 wherein elements of said output array represent portions of said pattern image which are evenly spaced along the height of said pattern image.

Claim 20

The method of claims 3, 4, 5, 8 or 9 wherein said pattern image consists of binary data.

Claim 21

The method of claims 3, 4, 5, 8 or 9 wherein said pattern image represents a character.

Claim 22

The method as in claims 3, 4, 5, 8 or 9 wherein said elements of said pattern image represent grey level of pixels.

Claim 23

The method of claims 3, 4, 5, 8 or 9 wherein additional features, not related to said transformation are used as additional elements of said feature vector.

Claim 27

The method of claims 3, 4, 5, 8 or 9 wherein selected elements of said feature vector are normalized.

Claim 31

The method as in claims 5 or 8 wherein said step of summing is a weighted summation.

Claim 32

The method as claimed in claims 8 or 9 wherein said first predetermined number is 5; and wherein said third predetermined number is eight.

Claim 33

The method as in claims 3 or 4 wherein elements of said intermediate array represent said regions of said pattern image which are evenly spaced across the width of said pattern image.

Claim 34

The method as in claims 3 or 4 wherein said elements of said intermediate array represent regions of said pattern image which are evenly spaced along the height of said pattern image.

Claim 39

The method of claims 3, 4, or 9 wherein weighted summation of said elements of said pattern image is used to create said intermediate array.