| 摘要 |
<p>PROBLEM TO BE SOLVED: To attain the code value control with the difference of picture quality secured in consideration of positions by outputting a coefficient code if the number of permitting times stored in a number-of-permitting times storage means is positive, outputting no coefficient code if the number of permitting times is not positive and then decreasing the stored number of permitting times by the number of codes which are outputted from a coefficient coding means. SOLUTION: A spatial threshold designating means 103 changes the threshold according to the position set on an image of a minimum coding unit(MCU), invalidates the code value control to assure the picture quality to the image data blocks located at a position near the center of the image and permits the deterioration of picture quality to the blocks located at the periphery of the image to validate the code value control. It is decided whether the value stored in a number-of-permitting times storage means 105 is positive or not. If the stored value is positive, a code is outputted. A coefficient coding part 102 codes the coefficient of the MCU and decreases the stored value of the means 105 by one every time a two-dimensional Huffman code is outputted.</p> |
