| 摘要 |
<p>An exposure level determination unit (33) determines, for a region of interest in an original image captured by a camera (2) using a first exposure level in a control cycle at a predetermined time point, a second exposure level which is an exposure level for the next control cycle, by calculating a transparent pixel saturation rate which is a ratio of transparent pixels having a saturated gradation value among transparent pixels in the region of interest, and changing the first exposure level according to the transparent pixel saturation rate.</p> |
