Method of inspecting surface of ceramic body

A method of inspecting a crack for a surface of a ceramic body, the method comprising:

• an image capturing step of performing, through a predetermined image capturing means, image capturing of a predetermined illuminated region of an inspection surface which is a partial surface of said ceramic body, said illuminated region being illuminated with at least one of first illumination light and second illumination light;
• a determination image generation step of generating, based on an image capturing result in said image capturing step, a determination image that is usable for determination of the presence or absence of any crack;
• and
• a determination step of determining the presence or absence of any crack on said inspection surface based on said determination image,
• wherein
• said first and second illumination light is emitted to said inspection surface from mutually different directions sandwiching said image capturing means,
• in said image capturing step, image capturing of said illuminated region is performed under illumination with at least one of said first and second illumination light,
• when a first image capturing result is defined as an image capturing result obtained by performing image capturing of said inspection surface with said image capturing means under illumination at least with said first illumination light, a second image capturing result is defined as an image capturing result obtained by performing image capturing of said inspection surface with said image capturing means under illumination at least with said second illumination light, and in said determination image generation step, a first determination image is generated based on said first image capturing result, and a second determination image is generated based on said second image capturing result,
• said first and second determination images are generated so that determination of the presence or absence of any crack on said inspection surface can be performed based on a difference between formation manners of shadow regions in said first and second determination images when said first and second determination images are compared with each other, and
• in said determination step, the presence or absence of any crack on said inspection surface is determined based on said first and second determination images,
• wherein in said determination image generation step, said first determination image is generated, based on said first image capturing result, as an image including only an image formation signal for a first color component, or as an image including an image formation signal for said first color component and an image formation signal for a color component other than said first color component, having a signal amount smaller than a predetermined threshold, and
• said second determination image is generated, based on said second image capturing result, as an image including only an image formation signal for a second color component, or an image including an image formation signal for said second color component and an image formation signal for a color component other than said second color component, having a signal amount smaller than a predetermined threshold, and
• wherein in said image capturing step, a result of image capturing with said image capturing means is generated as image capturing data in a predetermined data format,
• said determination image generation step is a determination image data generation step of generating determination image data which is image data of said determination image by acquiring a pixel value for a predetermined color component, as an image formation signal for said predetermined color component, from said image capturing data, and
• in said determination image data generation step, a first determination image data which is image data of said first determination image is generated based on first image capturing data generated as said first image capturing result, and a second determination image data which is image data of said second determination image is generated based on second image capturing data generated as said second image capturing result.