| 摘要 |
This process uses a bidirectional transformation by blocks for images representing highly animated scenes and also uses a differential coding of the transformation coefficients when the pictures show slightly animated scenes. The coding device mainly comprises a cosine transformation device, a subtractor, and inter-image decoding device, a multiplexer, a device for discriminating the blocks showing highly animated scenes and blocks showing slightly animated scenes. The latter device controls the multiplexer. The subtractor and the decoding device make it possible to calculate the difference between each transformation coefficient and the homologous coefficient of the homologous block in the preceding picture. Moreover, a weighting device makes it possible to transmit with a larger number of bits the coefficients or coefficient differences corresponding to the low spatial frequencies of the images. |
