| 摘要 |
PROBLEM TO BE SOLVED: To obtain the image processing unit in which production of loopback noise in the reproduction processing attended with number of reduced pixels is prevented, the circuit is simplified or a processing time is reduced. SOLUTION: DCT(discrete cosine transformation), quantization and Huffman coding are sequentially executed for image data, and in the case that the image is compressed by an image compression section 7, a 1st quantization table for quantization is in use. In the case of expanding an image by executing sequentially Huffman decoding, inverse quantization and inverse DCT processing, a 2nd quantization table whose horizontal vertical high frequency coefficients are smaller than those of the 1st quantization table is in use for the inverse quantization. |
