Inspection apparatus, image forming system, inspection method, and program

An image forming system having a function of inspecting a printed material for a smudge, the image forming system comprising:

• a printer that forms a print image on a paper sheet, and outputs a printed material on which the print image is formed;
• an image reader that reads the printed material output from the printer, and generates an inspection image;
• and
• a hardware processor that:
• performs position adjustment between a reference image serving as an inspection standard for the print image, and the inspection image;
• detects a region presumed to be a smudge on the printed material as a smudge candidate region, in accordance with a difference image generated from the reference image and the inspection image after the position adjustment;
• and
• determines whether the smudge candidate region is a false smudge candidate region resulting from a positional shift of an object in the print image, in accordance with the smudge candidate region detected by the hardware processor and difference data characteristics of the difference image.

An inspection method for inspecting a printed material for a smudge in accordance with an inspection image formed by reading the printed material on which a print image is formed, the inspection method comprising:

• performing position adjustment between a reference image serving as an inspection standard for the print image, and the inspection image;
• detecting a region presumed to be a smudge on the printed material as a smudge candidate region, in accordance with a difference image generated from the reference image and the inspection image after the position adjustment;
• and
• determining whether the smudge candidate region is a false smudge candidate region, in accordance with the smudge candidate region and difference data characteristics of the difference image.

A non-transitory recording medium storing a computer readable program for causing a computer to implement

• an inspection method for inspecting a printed material for a smudge in accordance with an inspection image formed by reading the printed material on which a print image is formed,
• the program causing the computer to execute:
• performing position adjustment between a reference image serving as an inspection standard for the print image, and the inspection image;
• detecting a region presumed to be a smudge on the printed material as a smudge candidate region, in accordance with a difference image generated from the reference image and the inspection image after the position adjustment;
• and
• determining whether the smudge candidate region is a false smudge candidate region, in accordance with the smudge candidate region and difference data characteristics of the difference image.