| 摘要 |
PURPOSE:To simply set an optimum control parameter to reduce an artificial error when picture data are compressed, that is, to predict the compression ratio of the picture before the compression. CONSTITUTION:A variance calculation device 18 obtains variance for each block as to a picture signal divided into blocks. When the variance of all blocks of one pattern image is obtained, the variance is fed to a median deciding device 19, in which the median is obtained. The median is fed to a coding information quantity decision device 20, where the coding information quantity is decided. The coding information quantity is fed to a scaling factor decision device 21, in which the scaling factor is decided. A quantization table 14 is generated based on the scaling factor. |
