IMAGE PROCESSING APPARATUS AND DOT BLANK DETECTION METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an image processing apparatus which can easily and efficiently detect a great amount of dot blank.SOLUTION: An image processing apparatus comprises: a printing data image acquisition unit which acquires a printing data image; an ink jet printer unit which prints on a reverse face of a check; a reverse face CIS unit which scans the reverse face of the printed check; a printing area clipping unit which clips a printing area R from the scanned image of the reverse face of the check as a clipped image; a character pixel number calculation unit which calculates the number of character pixels of each rectangular area having a prescribed width in a nozzle array direction YJ2 of an ink jet head for each of the printing data image and the clipped image; a ratio calculation unit which calculates a ratio of the number of character pixels of the clipped image to the number of character pixels of the printing data image included in each rectangular area; and a dot blank determination unit which determines occurrence of dot blank in the rectangular area when the calculated ratio of number of character pixels is the threshold value or less.