| 摘要 |
<p>A dynamic gain adjusting arrangement modifies video signals produced by image scanners to achieve high quality pictures. The arrangement compensates for amplitude distortions of the video signal caused by lens vignetting and variations in room lighting conditions. The video signals are compensated for these distortions by applying continuous gain adjustment to video information generated by a photosensor and by dynamically changing the gain adjustment parameters on a line-by-line basis according to an input signal reflecting the instantaneous background level.</p> |
