| 摘要 |
PROBLEM TO BE SOLVED: To transmit a compressed image by separating an image into required luminance information of a screen and other data depending on maximum/ minimum luminance in the image and giving the luminance signal and the color difference signals to respective coding decoding circuits. SOLUTION: A maximum luminance calculation circuit 64 and a minimum luminance calculation circuit 65 compare luminance values of all pixels in one frame of a multi-bit digital video signal 63 and output a maximum luminance value 67 and a minimum luminance value 68 respectively. A bit decomposition circuit 70 receives a multi-bit digital video signal 69, the maximum luminance value 67 and the minimum luminance value 68 after the lapse of one frame, decomposes them into digital video signals in 8-bit or lower and provides an output of a luminance signal (Y) 16 to an MPEG coder 19 and an output of a color difference signal (C) 71 to a color difference signal distribution circuit 72. Then major luminance information of the image as 8-bit data is converted into the luminance signal (Y) and a difference between the multi-bit digital video signal and the video signal resulting from decoding the scale of the luminance signal (Y) is converted into the color difference signal (C). |
