| 摘要 |
PROBLEM TO BE SOLVED: To easily, accurately and automatically confirm focusing precision of an image photographed on a film. SOLUTION: This scanner is provided with a means for detecting a primary difference or a secondary difference of a brightness data of the image on the film read by an imaging element, a means for determining a focused condition of the image on the film based on the detected difference, and a display means for displaying the focused condition on the determined film. When the primary difference or the secondary difference of a brightness data read from the image on the film is obtained, a peak is generated in a profile of the image in the difference to maximize an absolute value of the difference. The absolute value of the difference is compared with a preset focusing reference value, and a comparison value therein is calculated as the focusing precision. When the absolute value of the difference is larger than the focusing reference value, a contrast of the image profile is sufficiently large, the image is sharp, and the focused condition is determined thereby. The focused condition is not required thereby to be determined by the naked eye, and the image of the focused condition is automatically confirmed with high precision. |
