| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide automatic testing equipment which accurately determines the presence of foreign materials in an optical element and further, achieves reliable debris detection, even if an imaging device having defective pixels is used. <P>SOLUTION: This automatic testing equipment is provided with the imaging device for imaging a test image of the optical element, a pre-processing section for adjusting luminance distribution of the test image, and a foreign material candidate detector for picking out the foreign material candidate, by comparing the test image output from the pre-processing section with threshold for determining the foreign material candidate. The pre-processing section is designed to be constituted of a histogram extension processing section, which extends the gray scale width of the test image histogram produced by summarization of each pixel on the test image for each luminance up to the maximum gray scale level; and an image-smoothed reduction processing section, which reduces the test image with its gray scale width extended by the histogram extension processing section and then sets each luminance average between both a specific pixel, at a position associated with the pixel of a reduced image and a plurality of pixels, adjacent to the specific pixel in the test image to the luminance of each pixel in the reduced image. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
