摘要 |
<p>A video-apparatus comprises histogram modification means to match at least luminance signals (Y) for separate pixels to prescribed values. The histogram modification means comprises a first memory (3) with a first look-up table to correct the video luminance signals (Y), while a second memory (4) with a second look-up table is provided, the values within the second look-up table (4) being derived from the values in the first look-up table (3) and being applied to correct the color-difference signals (U and V). Preferably, in order to obtain a distribution of a rounding-off error over a pixel's neighbor, each of the channels for the luminance (Y) and color-difference signals (U and V) comprises a closed lsb (least significant bit) correction loop (14, 14') with a quantizer (15, 15') and a pixel memory (16, 16'), the input of the lsb correction loop being formed by the corrected luminance and corrected color-difference signals respectively. <IMAGE></p> |