| 摘要 |
PURPOSE:To prevent distortion in network point processing, by providing a constant relation between compared level and reading level, in a method varying a binarized tonal processing comparison level sequentially in matching with read-in scanning. CONSTITUTION:In video reading in whicn an analog video signal level V'B for black reading and an analog video signal level V'W for white reading have relation of V'B<V'W, a minimum value VB at black level of the binarized tonal processing comparison level is taken larger than the V'B and a maximum value VW of white level is taken smaller than the V'W. That is, the black reading level V'W of a video reading analog signal and the white reading level V'W are taken out and the binarized tonal processing comparison level is distributed between them. As a result, the output around the minimum level (V'B) and the maximum value (V'W) of the analog video signal can be uniformed with black or white, even when the binarized tonal processing comparison level is taken as the mininum value (VB) and the maximum value (VW). |
