| 摘要 |
PURPOSE: To quantity the uniformity of an image quality and to stabilize the quality of inspection by a method wherein a differential image obtained by a differential processing is converted into an image for a statistical processing and an image statistical value is determined on the basis of this image. CONSTITUTION: A plurality of gray images are obtained by picking up an image of a body to be inspected. The gray images are subjected to a color conversion processing and thereby images at color coordinates Yxy are obtained. An (x) image out of them is subjected to a differentiation processing, a mask 1001 is so put as to be superposed on an observed pixel of the (x) image, computation between nereby pixels is executed and the result is made a value of the pixel of a differential image at the same position as that of the observed pixel. This computation is executed for all pixels and thereby the differential image of the (x) image is obtained. It is executed also for a (y) image, the differential images thus obtained are added up and thus a differential image 1201 is obtained by the differentiation processing of the two images of (x) and (y). This image 1201 is subjected to binarization, an image obtained is divided into small regions of 4×4 and a processing result image 1301 is obtained. The rate of the pixels exceeding a threshold is determined for each of these small regions and the part in the whole wherein a color change is large is specified. This part is expressed by a numerical mark for each small region, the uniformity of the pixels is quantified and the distribution of the numerical marks is evaluated. |
