| 摘要 |
PURPOSE:To suppress the extension of a processing time at a minimum, by performing a first quantizing/coding process and a classifying process in parallel, performing the classifying process by using a code with fixed length outputted at the first quantizing/coding process, and counting the number of the codes with fixed length in which a classifying processing satisfies a specific condition. CONSTITUTION:Cosine transformation is performed by using a two-dimensional discrete cosine transform device 3, and 256 transform coefficients in one block can be obtained. Next, 255 transform coefficient AC components except one DC component arc quantized uniformly with fundamental quantizing width w0 by the first quantizing/coding device 4, and a pair of a coefficient number that is the code with fixed length and a polarity number can be obtained at every transform coefficient. The pair of the coefficient number and the polarity number is stored in a block buffer memory 8 transiently, and the coefficient number is sent to the classifying device 5. The classifying processing is performed in the classifying device 5, and a class number is outputted to a second quantizing/coding device 7. The second quantizing/coding device 7 transforms the code with fixed length of the transform coefficient AC component to a code with variable length. |
