| Name | Description |
|---|---|
| StdEntropyDecoder | This class implements the JPEG 2000 entropy decoder, which codes stripes in code-blocks. This entropy decoding engine decodes one code-block at a time. The code-blocks are rectangular and their dimensions must be powers of 2. Each dimension cannot be smaller than 4 and larger than 256. The product of the two dimensions (i.e. area of the code-block) cannot exceed 4096. Context 0 of the MQ-coder is used as the uniform one (uniform, non-adaptive probability distribution). Context 1 is used for RLC coding. Contexts 2-10 are used for zero-coding (ZC), contexts 11-15 are used for sign-coding (SC) and contexts 16-18 are used for magnitude-refinement (MR). This implementation also provides some timing features. They can be enabled by setting the 'DO_TIMING' constant of this class to true and recompiling. The timing uses the 'System.currentTimeMillis()' Java API call, which returns wall clock time, not the actual CPU time used. The timing results will be printed on the message output. Since the times reported are wall clock times and not CPU usage times they can not be added to find the total used time (i.e. some time might be counted in several places). When timing is disabled ('DO_TIMING' is false) there is no penalty if the compiler performs some basic optimizations. Even if not the penalty should be negligeable. |
