| 摘要 |
<p>PURPOSE:To reduce the deterioration of a picture quality, and to improve a compressing efficiency at the time of using an orthogonal transformation such as a cosine transformation by quantizing frequency components extracted based on an analyzed result separately from the other frequency components. CONSTITUTION:The frequency component data are transmitted from a cosine transforming part to a data storage part, stored, read out at every the prescribed number of blocks by a data analyzing part, and the data of both the common frequency component and the position are extracted. This frequency component is subtracted from the frequency component of each block, transmitted to a quantizing part, and quantized by removing the high frequency component at each block in an unexceeded degree. Moreover, the extracted frequency component data are quantized, transmitted to an encoding part, a code word is assigned to each frequency component, and each block is replaced with the code word in order to prepare a code sequence. The extracted frequency component data are also replaced with the code word, the prescribed number of blocks are defined as one pack, and outputted from a code outputting part.</p> |
