| 摘要 |
PURPOSE: To attain image compression in response to image quality of each image by deciding a quantization coefficient corresponding to a spatial frequency. CONSTITUTION: DCT data statistics obtained corresponding to the quantized DCT coefficients using a quantization table whose quantization coefficients are all 1 as a default and a set sum code quantity are input to a spatial frequency data quantity setting section 24. The spatial frequency data quantity setting section 24 sets set data quantity for each spatial frequency. A quantized table generating section 25 predicts a data quantity of coding data in the case of coding through the use of prescribed quantization coefficients. When the data quantity is less than the set data quantity set by the spatial frequency data quantity setting section 24, the quantization coefficients thus determined are adopted as the quantization table. |
