| 摘要 |
PURPOSE:To detect a defect high in an accuracy by comparing an uniformity evaluation value relating to the variable density uniformity of two dimensional variable density picture data according to a picture pattern attached on the surface of an object to be recognized with a threshold value and recognizing the defect part of the picture pattern. CONSTITUTION:An image pickup means for picking up the image of the two dimensional picture of the surface of the object 100 to be recognized is constituted of a light emitting element array 1 and a photoelectric transfer element array 2. For every constant area of the surface of the object 100 to be recognized having this picture pattern, a statistical uniformity evaluation value indicating the uniformity of the variable density of the two dimensional variable density picture picking up the image of this surface is calculated and when this uniformity evaluation value is below a constant threshold value, it is recognized that there is the defect part in the picture pattern. Thereby, even when there is a partial defect such as the picture pattern on the surface of the object 100 to be recognized, it can be effectively detected by a picture recognition device. |
