| 摘要 |
PROBLEM TO BE SOLVED: To provide an image pickup device which can automatically sample an image adequate for fingerprint matching from a fingerprint image inputted from an input device even if the image has variance in shading distribution or variance in ridge pattern thickness. SOLUTION: A current frame part 21 stores the latest image information in the fingerprint image inputted from the input device 1 and a previous frame part 22 stores image information which were stored in the current frame part 21. A pixel comparison part 31 compares correspondent pixel gray level information stored in the current frame part 21 with that of previous frame part 21. A gray level varying pixel count part 32 count pixels which increase in gray level and pixels which decrease in gray level according to pixel gray level comparison information. An image pickup timing determination part 33 determines image pickup timing by automatically detecting a proper fingerprint image for matching by using the result obtained by the gray level varying pixel count part 32 and outputs the proper fingerprint image to an output device 4 according to the judgment result. |
