Patent ID: 7430313

Claim:
A method for quantifying recurrent patterns in digital images comprising a plurality of pixels, the method comprising: (a) dividing a digital image into a plurality of overlapping value matrices; (b) selecting a matrix from the plurality of overlapping value matrices; (c) calculating a distance between the selected matrix and each of the remaining overlapping value matrices of the plurality of overlapping value matrices; (d) arranging the calculated distance as a row or a column in a distance matrix; and (e) repeating (b)-(d) for each value matrix of the plurality of overlapping value matrices selected as the matrix to provide a distance matrix; (f) calculating a local recurrence value for each row or column in the provided distance matrix, wherein the local recurrence value is the fraction of value matrices in that row or column whose distance from the matrix selected for that row or column is less than a selected cut-off distance; (g) calculating a value of a recurrence quantification analysis variable based on the calculated local recurrence values; and (h) outputting the calculated value as an indication of a characteristic of the digital image.