| 摘要 |
PURPOSE:To reproduce a picture with high picture quality by controlling stepwise a black level generating quantity in response to a black edge so as to reduce a rapid change in a UCR rate. CONSTITUTION:The processing device is provided with a means outputting a multi-stage K signal from r, g, b signals or C, M, Y signals and a means calculating a black edge quantity of a noted picture element from the r, g, b signals or C, M, Y signals. In this case, a black edge quantity calculation section 7 is made up of a black level calculation circuit 8 and an edge quantity calculation circuit 9 and calculates a black edge level (n) of a noted picture element to provide an output to a black level generating circuit 4. The black level generating circuit 4 controls the generation of a block level in multi-stage according to K=alphaxmin (C, M, Y). The correspondence between the black edge quantity n, alpha is formed in a table and the black level quantity K is changed in multistage in response to an output (n) from the black edge quantity calculation section 7. Thus, a sudden change in an UCR rate in a picture is suppressed and the picture quality is improved. |
