| 摘要 |
PURPOSE:To improve the compression rate of information quantity and to improve the picture quality by using the visual characteristic in the case of quantization of a conversion value obtained through data conversion of a picture signal. CONSTITUTION:An inputted picture signal is divided into plural blocks comprising plural adjacent picture elements for each pattern and horizontal and vertical picture elements by a block division circuit 1 to convert the signal into a picture data string for each block. The picture element data string for each block is subject to data conversion by a data conversion circuit 2 and stored in a storage circuit 3. In the case of quantizing the converted value, the quantizing characteristic of each block is decided from an average brightness of the surrounding blocks through the application of the visual characteristic whose difference sensitivity is deteriorated when a brightness difference from the surrounding parts is large, a block having a large brightness difference from the surrounding parts is quantized roughly and a block with a small brightness difference is quantized minutely. Thus, the compression rate of the information quantity is improved and the reproduced picture quality is improved in the visual sense. |
