| 摘要 |
<p>PURPOSE:To control the code volume with high precision by generating a quantization table matched with a picture. CONSTITUTION:A picture compressing device 30 is provided with a DCT operation part 32 for DCT-operating picture data, a quantizing part 33 for operating the quntization of the DCT operation output in accordance with values of a quantization table RAM 34, a histogram device 35 for taking the histogram of respective frequency components of the DCT operation output, and a Huffman code coding part 37 for coding the output of the quantization part 33 to the Huffman code in accordance with the values of a Huffman table ROM 36 and writing the generated code volume of each block in a code volume RAM 38. Further, a code volume control part 39 is provided which rewrites a fundamental table based on the histgram of respective frequency components from the histogram device 35 and calculates the overall generated code volume from the generated code volume of each block in the code volume RAM 38 and generates an optimum quantization table and performs the control to predict the generated code volume of each block quantized in accordance with the generated quantization table.</p> |
