| 摘要 |
<p>PURPOSE:To stabilize picture quality by providing a high efficiency encoder means, a means to find temporary encoding quantity at every image unit, a means to convert the temporary encoding quantity, a means to perform setting based on target encoding quantity and a means to control generated encoding quantity. CONSTITUTION:An image signal is supplied to an image information change mode detector 5 and a predictive subtractor 2. The detector 5 detects the degree of change of image information, and generates information to be used in the setting of a quantization scale to be decided by a quantization controller 6 corresponding to the degree of change of the image information at every block sequentially segmented from the image signal, and supplies it to the controller 6. The controller 6 outputs the information to set the quantization scale supplied from a reference quantization scale setting part 17 via a switch 18 and decided in advance and the information used in the setting of the quantization scale from the detector 5 to a quantizer 4. In the case the image signal with large change of image content is quantized, the controller 6 sets the quantization scale at a large value.</p> |
