| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic contrast correction circuit that can be realized on a simple configuration. SOLUTION: In this automatic contrast correction circuit which converts luminance, equal to or higher than fixed luminance, on the higher luminance side of input image data into the highest luminance, also converts luminance, equal to or lower than fixed luminance, on the lower luminance side into the lowest luminance and linearly expands the luminance in the meantime from the lowest luminance to the highest luminance in accordance with the luminance, the luminance of the lower luminance side, the luminance of the higher luminance side, the number of neglected pixels on the lower luminance side and the number of neglected pixels are preliminarily set, the number of pixels that are equal to or lower than the set luminance of the lower luminance side and the number of pixels that are equal to or higher than the set luminance of the higher luminance side are counted among pieces of the input image data, the respective numbers of counted pixels are compared with the number of the neglected pixels, the luminance of the lower luminance side and the luminance of the higher luminance side are increased/reduced so as to make the respective numbers of the pixels to be the closest, and luminance at the time when an increase/reduction direction is inverted is respectively defined as the luminance of the lower luminance side and the luminance of the higher luminance side which are searched for. |
