Rate-distortion estimation for fast JPEG2000 compression at low bit rates

In JPEG2000 block coding, all coding passes are generated before rate allocation is performed among code-blocks. Unwanted passes are then discarded. For low bit-rate coding, this results in discarding of a large number of coding passes. In this letter, we propose a rate-distortion estimation method that enables pre-compression rate-distortion optimization to be carried out, wherein only the required passes need to be coded. Experiments using the proposed technique demonstrate speedup factors ranging from 1.17 to 1.78 at 0.0625 bpp, for JPEG2000 compression.