Patent ID: 7042439

Claim:
A method of determining a movement vector between two digital images comprising: (a) capturing a first MxN dimensional image and a second MxN dimensional image, wherein each image comprises MxN data values and M and N are greater than 2; (b) calculating a directional correlation value for a plurality of directional shifts between said first image and said second image; (c) identifying a minimum directional correlation value from said directional correlation values; (d) determining if the minimum directional correlation value calculated is less than a predetermined threshold, and (i) if so, identifying a movement vector associated with said minimum directional correlation value, and (ii) if not, compressing said first image and said second image into (M/S)×(N/S) dimensional images comprising (M/S)×(N/S) data values, wherein S is an integer greater than 1, and wherein the value of each data point of a compressed image is an average of S×S data values of the original image which the compressed data point is replacing, such that said first image and said second image have a smaller dimension and repeating (b) through (d) with incremented S until said movement vector is identified, wherein M and N are even multiples of S.