Patent Document ID: 20120206593
Application ID: 13352427
Patent Status: 0

Claim One:
1. A defect detection apparatus for detecting a defect on an imaged object surface from a multi-valued image captured by an imaging device, the defect detection apparatus comprising: a size setting and accepting device for accepting a setting of a size of a defect as a detection object; a size storing device for storing the size of the defect for which the setting has been accepted by the size setting accepting device; a direction instruction accepting device for accepting an instruction in relation to a first direction in which a background pattern is uniformly continuous; a direction storing device for storing the first direction for which the instruction has been accepted by the direction instruction accepting device; an image reducing device for generating a reduced image obtained by reducing the multi-valued image in the stored first direction using an image reduction ratio according to the size of the stored defect; a filter processing device for performing filter processing in the first direction on the reduced image for removing a defect in the reduced image; an image enlarging device for generating a first enlarged image obtained by enlarging the reduced image, subjected to the filter processing by the filter processing device, in the first direction with an image enlargement ratio corresponding to the reciprocal of the image reduction ratio; and a difference calculating device for generating a difference image by calculating a difference between the multi-valued image and the first enlarged image.