Being the manner which inspection manner of surface discontinuity, projects the illumination in production manner of the surface discontinuity survey instrument and

摘要

PROBLEM TO BE SOLVED: To provide a surface flaw inspecting method which enables the obtaining of a result near to a visual inspection result at the time of the inspection of a surface flaw, a surface flaw inspecting device, a steel plate manufacturing method and a steel plate manufacturing apparatus.;SOLUTION: In the method for inspecting the surface flaw of a surface to be inspected by projecting illumination light on the surface to be inspected to image the surface to be inspected, the image obtained by imaging is divided into a large number of longitudinally and laterally arranged pixels and the surface flaw is detected by calculating a color difference with respect to all of the respective pixels. The color difference is calculated only from the brightness of a region containing the target pixel and the brightness of a region separated from the target pixel by predetermined distance.;COPYRIGHT: (C)2010,JPO&INPIT