| 摘要 |
PURPOSE:To visually improve the picture quality of a dynamic picture encoder by providing a means preventing the transfer by masking the high-pass component of the orthogonal conversion when the quantization step width is more than the constant value in the device performing the inter-frame/intra-frame orthogonal conversion coding of a dynamic picture signal. CONSTITUTION:A high-pass mask circuit 16 receives the quantization step width designated by a buffer memory 14. When it is higher than the prescribed value, only the high-pass component is masked by the prescribed mask pattern. Therefore, only the low-pass component is transferred to a quantizer 5 to be quantized, resulting in reducing the information amount stored in the buffer memory 14. When it becomes lower than the prescribed value, the buffer memory 14 designates finer quantization step width to the quantizer 5 and a reverse quantizer 6. Thus, the only low-pass component of the picture is quantized with finer step width by the quantizer 5, permitting a viewer to clearly view the visually important low-pass component. |
