Patent ID: 8634651

Claim:
A method of identifying the location of a first target image pattern in an image comprising: generating, for each one of W individual sets of pixel values of an image, a corresponding set of difference measure values, said corresponding set of difference measure values including at least one of a first difference measure value, a second difference measure value, or a third difference measure value, said first difference measure value indicating a measure of the difference between pixel values in said individual set of pixel values and a first reference set of pixel values, said second difference measure value indicating a measure of the difference between pixel values in said individual set of pixel values and a second reference set of pixel values, said third difference measure value indicating a measure of the difference between pixel values in said individual set of pixel values and a third reference set of pixel values, said W sets of pixel values including pixel values from at least two consecutive rows or columns of the image; generating a first sum of difference values from at least some values in the generated sets of difference measure values, said sum of difference values indicating a detected amount of difference between a first two dimensional array of pixel values and a two dimensional target pattern; and making a decision as to the location of the first target pattern within said image based on at least said first sum of difference values.