Printed matter inspection device and printed matter inspection method

A printed matter inspection method comprising:

• a detection step of detecting a streaky concentration defect that extends in a first direction from a printed matter;
• an intensity calculation step of calculating a basic streak intensity that is an intensity of the concentration defect;
• a streak near-field area specification step of specifying a streak near-field area that is continuous from an area of the concentration defect of the printed matter, in which a variation of image feature amounts is within a predetermined first range;
• a streak near-field area information acquisition step of acquiring color information and frequency feature information on the streak near-field area;
• an outer peripheral area specification step of specifying an outer peripheral area that is in contact with the streak near-field area;
• an outer peripheral area information acquisition step of acquiring frequency feature information on the outer peripheral area;
• a visibility determination step of determining visibility of the concentration defect on the basis of the basic streak intensity, the color information and the frequency feature information on the streak near-field area, and the frequency feature information on the outer peripheral area;
• and
• a determination step of determining whether the quality of the printed matter is good or not at least on the basis of the visibility.

A computer-readable non-transitory recording medium that stores a printed matter inspection program causing a computer to execute:

• a detection step of detecting a streaky concentration defect that extends in a first direction from a printed matter;
• an intensity calculation step of calculating a basic streak intensity that is an intensity of the concentration defect;
• a streak near-field area specification step of specifying a streak near-field area that is continuous from an area of the concentration defect of the printed matter, in which a variation of image feature amounts is within a predetermined first range;
• a streak near-field area information acquisition step of acquiring color information and frequency feature information on the streak near-field area;
• an outer peripheral area specification step of specifying an outer peripheral area that is in contact with the streak near-field area;
• an outer peripheral area information acquisition step of acquiring frequency feature information on the outer peripheral area;
• a visibility determination step of determining visibility of the concentration defect on the basis of the basic streak intensity, the color information and the frequency feature information on the streak near-field area, and the frequency feature information on the outer peripheral area;
• and
• a determination step of determining whether the quality of the printed matter is good or not at least on the basis of the visibility.