| 摘要 |
PROBLEM TO BE SOLVED: To realize detection of a video start line, a video end line and a caption end line with high accuracy by updating a black level being a line discrimination criterion for each field. SOLUTION: The wide aspect ratio video image detection circuit consists of a level detection means 101 to detect a maximum level 137 and a minimum level 139 of a luminance signal 135 from the luminance signal of an input video signal for each field and of a video detection means 107 that outputs a position 157 of the video start line and a position 159 of the video end line based on the luminance signal, the maximum level and the minimum level as a count according to a horizontal synchronizing signal 145.
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