Defective nozzle estimation device, defective nozzle estimation method, defective nozzle estimation program, printing device, and method for manufacturing printed matter

A defective nozzle estimation method of estimating a defective nozzle of a plurality of ink jet heads of a printing device that prints a printed matter on a print medium by jetting inks from nozzles of the ink jet heads on the basis of print source data, the plurality of ink jet heads jetting inks of different colors from the nozzles, the defective nozzle estimation method comprising:

• an image defect position acquisition step of acquiring a position of an image defect of the printed matter caused by the defective nozzle in imaging data based on a captured image in which the printed matter is imaged by a scanner;
• a first pixel value acquisition step of acquiring a first pixel value at the position of the image defect of the imaging data;
• a second pixel value acquisition step of acquiring a second pixel value at a position corresponding to the position of the image defect of reference data, which is the print source data or reference imaging data based on a reference captured image in which a reference printed matter is imaged by the scanner;
• and
• a defective nozzle candidate estimation step of estimating at least one defective nozzle candidate, which is a cause of the image defect of the printed matter, from the first pixel value and the second pixel value using a learning model.