Patent ID: 7532738

Claim:
A print medium quality adjustment system comprising an inspection watermark medium output device that outputs an inspection watermark medium to be used to inspect a print medium; and a watermark quality inspection device that inspects the quality of a watermark in the print medium, wherein: a. the inspection watermark medium output device includes; (1) an inspection watermark signal generation unit that generates a single inspection watermark signal or a plurality of inspection watermark signals, to be used for inspection, generates a watermark signal image by disposing the inspection watermark signal(s) in an arbitrary arrangement, and generates inspection training data having N-dimensionally encoded data indicating a numerical value, which are obtained by digitizing the inspection watermark signal(s), N being a positive integer equal to or greater than 2; and (2) an inspection medium output unit that outputs an inspection watermark medium to be used for inspection, created by printing the inspection watermark signal(s) onto a medium; and b. the watermark quality inspection device includes: (1) an input unit that takes in the inspection watermark medium as a multi-value gradation input image; (2) a signal detection unit that detects a signal embedded in the input image and extracts embedded watermark information from the signal; (3) a print quality judgment unit that judges watermark quality by comparing the watermark information with the inspection training data input thereto; and (4) a print adjustment value output unit that outputs, based upon the results of the quality judgment, a print adjustment value to be used to improve the print quality, wherein the print adjustment value output unit determines an adjustment value, which is dependent on the position assumed at the print medium, in correspondence to the difference between the inspection training data and the watermark signal detected by the signal detection unit and then output the adjustment value thus determined as the print adjustment value, wherein the inspection training data are obtained by using at least part of the watermark information, and wherein the print quality judgment unit divides adjustment values, each determined in correspondence to a specific position at the print medium, into groups each representing one of an arbitrary number of areas, sets an area with an adjustment value equal to or greater than a predetermined threshold value as a high-error area and designates the high-error area as a dummy watermark area with no information contained therein.