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JPEG2000实现的源码

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/*      (C) Copyright 1999 by Wenjun Zeng,                              */
/*      Sharp Labs. of America.                                         */
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This is a stand-alone software package for palette-based lossless JPEG2000 
option that has been adpoted into JPEG2000 working draft. It serves as a 
pre-processing (convert color image into an index image and a color table, 
reindex the table for more efficient compression of the index image) to the 
rest of the VM.

It is intended to be used for lossless compression of images with a limited 
number (<=256) of colors such as graphic images. For this types of images, 
it often offers significant performance improvment (up to one order of 
magnitude in terms of file size) over non-palette-based JPEG2000. 
Its performance is usually better ro comparable to GIF.

To compile, type "make"

For an example of how to use this software, see the two scripts under the 
"example" directory: palette_encode and palette_decode


program description:
--------------------
ppm2index:

  convert a color image (in ppm format) to an index image and a color table 
  (with random indexing). Currently, the program is limited to only accept 
  an input ppm image  with up to 256 colors.          

reindex:

  suboptimal reindexing of color table for more efficient lossless compression
  of the index image. This version only accepts .pgx file format (for index 
  map). It will also read in the color table, reorder it correspondingly, and 
  output a new color table.                            

  For details about this reindexing scheme, see the file "reindex.ps"

index2ppm:

  reconstruct a .ppm file from the index image (in .pgx format) and the color 
  palette table 

pgm2pgx
pgx2pgm:

  utility programs, conversion between pgm format and pgx format


Additional notes:
-----------------
1) Currently, the programs are limited to only deal with 
  an image  with up to 256 colors. 
2) The final bitstream size should include the size of the color table.