| 摘要 |
PROBLEM TO BE SOLVED: To greatly decrease the amount of data to be processed and shorten the processing time, and prevent a decrease in discrimination precision due to image distortion, a position shift, a partial defect, etc., of a read image by discriminating an unevenness pattern according to compressed image data and prepared reference image data. SOLUTION: This device is equipped with a read means 13 for reading the unevenness pattern with high resolution, a center position calculating means 15 which calculates the center position of an object 11 according to image data obtained from the read means 13, an image compressing means 17 which performs compression within a range wherein the distribution of the pattern part on the top surface of the object 11 can be discriminated, and a collating means 19 which collates the compressed image data with the prepared reference image data. The image is compressed at a desired compression ratio within the range wherein the distribution of the pattern part can be discriminated, so the amount of data to be processed can be decreased without spoiling features of the unevenness pattern. Further, the unevenness pattern is discriminated according to the distribution of the pattern, so a decrease in discrimination precision due to the image distortion, etc., of the read image is reducible. |
