Inspection device, inspection method, and inspection program

An inspection method involving use of an inspection device, comprising the steps of:

• obtaining an inspection image, which is an image used to determine presence or absence of a defect inside an inspection target;
• determining presence or absence of a defect in the inspection target with use of a restored image generated by inputting the inspection image into a generative model, the generative model being constructed by machine learning so that the generative model generates a new image having a similar feature to that of an image input into the generative model, the generative model being constructed by using, as training data, a first ultrasonic testing image of an inspection target in which a defect is absent;
• and
• extracting, as an inspection target area, an area sandwiched between two peripheral echo areas from a second ultrasonic testing image so as to generate the inspection image, the second ultrasonic testing image being an image of an echo of an ultrasonic wave propagated in the inspection target, each of the two peripheral echo areas being an area where an echo coming from a periphery of an inspection target portion of the inspection target appears repeatedly,
• wherein, in the step of obtaining the inspection image, the inspection image is generated by the step of extracting.

A non-transitory computer readable medium storing an inspection program configured to cause a computer to function as an inspection device, the inspection program causing the computer to carry out:

• an inspection image obtaining step of obtaining an inspection image, which is an image used to determine presence or absence of a defect inside an inspection target;
• a defect presence/absence determination step of determining presence or absence of a defect in the inspection target with use of a restored image generated by inputting the inspection image into a generative model, the generative model being constructed by machine learning so that the generative model generates a new image having a similar feature to that of an image input into the generative model, the generative model being constructed by using, as training data, an ultrasonic image of an inspection target in which a defect is absent;
• and
• an inspection image generating step of extracting, as an inspection target area, an area sandwiched between two peripheral echo areas from an ultrasonic testing image so as to generate the inspection image, the ultrasonic testing image being an image of an echo of an ultrasonic wave propagated in the inspection target, each of the two peripheral echo areas being an area where an echo coming from a periphery of an inspection target portion of the inspection target appears repeatedly, in the inspection image obtaining step, the inspection program causes the computer to obtain the inspection image generated in the inspection image generating step.