| 摘要 |
<p>PURPOSE:To heighten the compression efficiency of original picture data by further dividing the set of the DC components of an orthogonal transform coefficient on which a compression processing such as normalization or coding, etc., is applied into plural blocks, and compressing the data by performing an orthogonal transform processing on every block again. CONSTITUTION:Orthogonal transform is applied on the original picture data at every block at a transformation part 11, and the orthogonal transform coefficient F(u,v) is found, and the coefficient F is divided into the DC component and an AC component. The DC component is stored in a DC component memory 13, and the AC component in an AC component memory 14, and a normalization processing and a coding processing are performed on data of one picture read out of the memories 13 and 14 at a compression part 12. Picture data of one picture is stored in the memory in a state where it is divided into the AC component and the DC component, or is transmitted to a receiver. Compression data from the memory or the receiver is supplied to an expander 22, and an expansion processing is applied on the data of AC component, and the coefficient F is recovered, then, it is stored in the AC component memory 24. Also, the original DC component of the DC component obtained by the reverse orthogonal transform of the DC component at every block at a reverse transformation part 21 is stored in the DC component memory 23.</p> |
