Patent ID: 7391884

Claim:
A method, comprising: calculating a calibration correlation value to compensate for an error introduced by a scanning process implemented to produce a scanned image; compare properties of an original digital image, the original digital image being defined by a matrix having dimensions m×n to properties of a scanned image of the original digital image, the scanned image of the original digital image being defined as a matrix having dimensions k×l, to produce a correlation value, wherein during the comparison of the original digital image and the scanned image of the of the original digital image the scanned image is scaled to match dimensions with the original digital image by; dividing the scanned image of the original digital image into m×n blocks, each block having dimensions k·P/m in the x dimension and l·P/n in the y dimension, wherein P is a resolution of dots per inch by which the second image was scanned at; summing and averaging pixel value parameters associated with each pixel in each block respectively; and determining the correlation value between the scanned image and an original digital image, wherein the scanned image is included in a digital file; subtracting the calibration correlation value from the correlation value to produce a difference; and generating a signal indicating whether the difference exceeds a threshold.