| 摘要 |
<p>PURPOSE:To vary the accuracy of an arithmetic operation and processing time for picture coding as necessary. CONSTITUTION:A picture coder is provided with a frame memory 31 storing picture data, an orthogonal transformation section 32 reading the picture data to implement an orthogonal transformation operation in the unit of blocks, a quantization section 33 executing quantization operation according to the value of a quantization table RAM 34, an entropy coding section 35 applying entropy coding to the output of the quantization section 33 according to the value of a table ROM 36 for entropy coding. The orthogonal transformation section 32 is provided with a bit length controller controlling the length of a bit of data in a first dimension and the bit length of the data in the first dimention is decreased when the speed is required and the bit length is increased when the accuracy is required.</p> |
