Storage medium storing computer program and inspection apparatus

An inspection apparatus comprising:

• a controller;
• and
• a memory storing a set of program instructions, the set of program instructions, when executed by the controller, causing the inspection apparatus to perform:
• acquiring target image data indicating a target image including an object of an inspection target, the target image data being generated by using an image sensor;
• inputting the target image data into an image generation model to generate first reproduction image data, the first reproduction image data indicating a first reproduction image corresponding to the target image, the image generation model being a machine learning model including an encoder configured to extract a feature of image data that is input and a decoder configured to generate image data based on the extracted feature;
• generating first difference image data indicating a difference between the target image and the first reproduction image by using the target image data and the first reproduction image data;
• inputting the first difference image data into a feature extraction model to generate first feature data indicating a feature of the first difference image data, the feature extraction model being a machine learning model including an encoder configured to extract a feature of image data that is input;
• and
• detecting a difference between the target image and a comparison image by using the first feature data and reference data, the reference data being data based on second feature data generated by using comparison image data indicating the comparison image, the second feature data being generated by inputting second difference image data into the feature extraction model, the second difference image data indicating a difference between the comparison image and a second reproduction image corresponding to the comparison image.