| 摘要 |
<p>PURPOSE:To decrease quantization errors and to improve the quality of a restored image by providing a second table to store such a quantization limit band information that the mean square error of the same frequency components of an image data is minimum in relation to a quantization bit number supplied by a first table which stores allocated bit number information corresponding to the frequency components of an image data. CONSTITUTION:The titled device is provided with a first table to store allocated bit number information corresponding to the frequency components of an image data after being subjected to block orthogonal transformation, a second table to store such a quantization limit band information that the mean square error of the same frequency components of an image data is minimum in relation to a bit number supplied by the first table, and a quantizer 5 to quantize an image data based on the information in the first and the second tables. Accordingly, since the quantization limit band varies corresponding to the variation in allocated bit number generated from the bit allocation table 4, the quantization errors are decreased. As a result, the quality of a restored image can be improved.</p> |
