| 摘要 |
<p>PURPOSE:To enable to select the picture of high quality according to the demands of users, by discarding the fraction and making quantization of the conversion co-efficient obtained by vertical cross conversion against the division block using the threshold value of discarding and coefficient quantization step width which are set in advance, forming the encoded data, transmitting or storing the encoded data, and decoding it at the expansion side. CONSTITUTION:8-bit picture data of one picture element is divided horizontally into 16 picture elements and vertically 16 picture elements, and multiplication of the 2-dimension discrete cosine conversion matrix with its transposed matrix is executed at converter 1-16, the conversion coefficient matrix is obtained. The output of coefficient discarding device 1-17 is uniformly quantized at step width 1-12 by coefficient quantizing device 1-18, and allotted with variable code specified in advance by encoder 1-19. The encoded data 1-21 generated by the encoder is transferred or stored as compressed data 1-13. The expanding device takes reverse procedure; the reproduced conversion coefficient reversely converted by 2-dimension discrete reverse conversion device 2-17, and the decode picture signal 2-18 is outputted.</p> |
