| 摘要 |
PURPOSE:To encode detailed information of a picture as a sharp picture data by quantizing an orthogonal transformation data classified by a classification means according to a quantization table in response to its frequency component. CONSTITUTION:A quantization means comprising a quantization section 33, a quantization step control section 34, and a rank discrimination section 42 is provided with a classification means to classify an orthogonal transformation data according to its frequency component and with plural quantization tables relating to the frequency components of the orthogonal transformation data. Then the orthogonal transformation data resulting from a picture signal subjected to orthogonal transformation at an orthogonal transformation means 32 is classified in response to its frequency component and the orthogonal transformation data is quantized according to a quantization table in response to the classified frequency component. Thus, detailed information of the picture is coded by a coding means 35 as a sharp picture data without increase of the information quantity of coding. |
