| 摘要 |
PURPOSE:To convert colors at a high speed and with high accuracy by calculating a color component ratio after subtracting data obtained by giving logarithm conversion to luminance data for each picture element from density data obtained by giving the logarithm conversion to the color picture data separated into each color for each picture element. CONSTITUTION:Picture data inputted to a CCD color sensor 45 is separated into each color and converted into signals (y), (m) and (c) after shading correction and complementary color conversion. These signals (y)-(c) are converted into density data Y, M and C by logarithm converting circuits 51, 52 and 53 and also supplied to subtraction circuits 56, 57 and 58 respectively. An addition circuit 54 adds the signals (y)-(c) together for calculation of the luminance data and supplies this data to the circuits 56-58 through a logarithm circuit 55. The subtraction outputs are sent to comparators 63, 64 and 65 and outputted via an AND gate 66 when a desired color component ratio is detected. Then different color component data which are previously set are outputted from a selector 59. In such a way, the conversion of colors can be performed at a high speed and with high accuracy. |
