Patent ID: 7864349

Claim:
A system for detecting errors in a printed copy, the system comprising: one or more computer memories having one or more digitized source images; one or more scanners that scan one or more printed copies to create one or more corresponding scanned images; an alignment process that creates an initial replacement image from the scanned image by performing an interpolation to generate additional lines in the scanned images to correspond to the digitized source images, and aligns the replacement scanned image with the digitized source image on a page by page, line by line, and pel by pel basis, the interpolation performed by tagging each line of the scanned image with one or more tag pairs associated with one or more synchronization strips embedded in the digitized source image; and a comparison process that compares one or more source pels of the digitized source image with one or more corresponding scanned pels of the initial replacement image by: dilating the replacement image; eroding the source image; bit-wise and'ing the corresponding one-bit pel values of the dilated replacement image and the eroded source image to produce a first intermediate result; bit-wise exclusive-or'ing the first intermediate result with the one-bit pel values of the eroded source image to indicate the pel locations of missing ink in the scanned image.