State determination apparatus, state determination method, and computer-readable recording medium

A state determination method comprising:

• acquiring, as a fixed image, each of time-series images obtained by continuously shooting a rotating object with an image capturing apparatus via a first optical device that rotates and emits incident light;
• calculating a displacement amount of a plurality of specific points on the object, using each of the acquired fixed images, and, with one of the plurality of specific points as a reference specific point, calculating a difference between the displacement amount of the reference specific point and the displacement amount of each specific point other than the reference specific point;
• calculating, as an out-of-plane displacement, a displacement of a surface of the object on an image plane of the image capturing apparatus following movement of the object in a normal direction of the image plane, using the difference;
• calculating, as an in-plane displacement, a displacement of the surface of the object on the image plane following movement of the surface of the object in a direction along the surface, using the difference and the out-of-plane displacement;
• and
• specifying an abnormality of the object, based on a distribution of the in-plane displacement or a temporal change of the out-of-plane displacement.

A non-transitory computer-readable recording medium including a program recorded thereon, the program including instructions that cause a computer to carry out:

• acquiring, as a fixed image, each of time-series images obtained by continuously shooting a rotating object with an image capturing apparatus via a first optical device that rotates and emits incident light;
• calculating a displacement amount of a plurality of specific points on the object, using each of the acquired fixed images, and, with one of the plurality of specific points as a reference specific point, calculating a difference between the displacement amount of the reference specific point and the displacement amount of each specific point other than the reference specific point;
• calculating, as an out-of-plane displacement, a displacement of a surface of the object on an image plane of the image capturing apparatus following movement of the object in a normal direction of the image plane, using the difference;
• calculating, as an in-plane displacement, a displacement of the surface of the object on the image plane following movement of the surface of the object in a direction along the surface, using the difference and the out-of-plane displacement;
• and
• specifying an abnormality of the object, based on a distribution of the in-plane displacement or a temporal change of the out-of-plane displacement.