readme

著名压缩算法的实现

+======================================================+
|  Introduction to the losslessy compression schemes   |
|                Description of the files              |
+------------------------------------------------------+
| From David Bourgin (E-mail: [e-mail]) |
| Date: 12/10/95                          VERSION: 1.5 |
+======================================================+

                          ------ BE CARE ------
The file 'compress.txt' is copyrighted. (c) David Bourgin - 1994/1995
Permission to use this documentation for any purpose other than
its incorporation into a commercial product is hereby granted without fee.
Permission to copy and distribute this documentation only for non-commercial use
is also granted without fee, provided, however, that the above copyright notice
appears in all copies, that both that copyright notice and this permission notice
appear in supporting documentation. The author makes no representations about
the suitability of this documentation for any purpose. It is provided "as is"
without express or implied warranty.

The source codes you obtain with this file are *NOT* covered by the same
copyright, because you can include them for both commercial and non-commercial
use. See below for more infos.

The source code files (codrle1.c, dcodrle1.c, codrle2.c, dcodrle2.c, codrle3.c,
dcodrle3.c, codrle4.c, dcodrle4.c, codhuff.c, dcodhuff.c, dcodlzw.c, dcodlzw.c)
are copyrighted.

History of the different versions of the packages:
- Version 1.0: 22/5/94
  The first package is available by anonymous ftp.
  RLE1, RLE2, RLE3, RLE4 and Huffman compressers and decompressers are available
- Version 1.1: 22/9/94
  Huffman compresser and decompresser have been fixed (bug of memory
  allocation) and file compress.txt is modified
- Version 1.2: 3/4/95
  LZW compresser is available
- Version 1.3: 16/5/95
  LZW decoder is added and LZW compresser/decompresser are modified. The file
  compress.txt is updated
- Version 1.4: 24/7/95
  RLE1 compresser is faster.
  RLE2 compresser is fixed (a bug appears when the less frequent byte in data
  to compress is met three times consecutively).
  RLE3 and RLE4 compressers are modified (they didn't provide the full
  compression as they should. And the files in input may cause an error if the 
  pattern had a size of 256 bytes).
  Huffman and LZW compressers have been modified to speed up the process. But
  LZW compresser has a bug (which comes from a previous version but it didn't
  appear on benchmarks but appeared by trying to compress the file
  'compress.txt'). It will be modified very soon. The decompresser of LZW is
  okay.
  Samples in compress.txt have been changed for RLE2, RLE3, and RLE4 because
  unaccurate.
- Version 1.5: 12/10/95
  The LZW compresser is fixed up. The bug occurred only when the dictionary
  was reset. It remains compatible with previous version.

The source codes I provide have no buggs (!) but being that I make them
available for free I have some notes to make. They can change at any time
without notice. I assume no responsability or liability for any errors or
inaccurracies, make no warranty of any kind (express, implied or statutory)
with respect to this publication and expressly disclaim any and all warranties
of merchantability, fitness for particular purposes. Of course, if you have
some problems to use the information presented here, I will try to help you if
I can.

If you include the source codes in your application, here are the conditions:
- You have to put my name in the header of your source file (not in the
excutable program if you don't want) (this item is a must)
- I would like to see your resulting application, if possible (this item is not
a must, because some applications must remain secret. But please, if possible,
let me see your application. I won't disclose it.)
- Whenever you gain money with your application, I would like to receive a very
little part in order to be encouraged to update my source codes and to develop
new schemes (this item is not a must). Contact me by e-mail if you want to do
that.

This package must be distributed without fees (except to store and send it,
but this must be made at low cost!). And the package must be distributed
fully.

The package is given by the following structure tree:

codecs.dir +--> francais +--> lisezmoi    (French version of the file *TO READ*
           |             +--> compress.txt(French help to change the codecs and
           |             |                 to understand RLE, Huffman, and LZW
           |             |                 encoding/decoding)
           |             +--> codrle1.c   (French version of RLE1 encoding)
           |             +--> codrle2.c   (French version of RLE2 encoding)
           |             +--> codrle3.c   (French version of RLE3 encoding)
           |             +--> codrle4.c   (French version of RLE4 encoding)
           |             +--> codhuff.c   (French version of Huffman encoding)
           |             +--> codlzw.c    (French version of LZW encoding)
           |             +--> dcodrle1.c  (French version of RLE1 decoding)
           |             +--> dcodrle2.c  (French version of RLE2 decoding)
           |             +--> dcodrle3.c  (French version of RLE3 decoding)
           |             +--> dcodrle4.c  (French version of RLE4 decoding)
           |             +--> dcodhuff.c  (French version of Huffman decoding)
           |             +--> dcodlzw.c   (French version of LZW decoding)
           |
           +--> english  +--> readme      (English version of the file *TO READ*
                         +--> compress.txt(English help to change the codecs and
                         |                 to understand RLE, Huffman, and LZW
                         |                 encoding/decoding)
                         +--> codrle1.c   (English version of RLE1 encoding)
                         +--> codrle2.c   (English version of RLE2 encoding)
                         +--> codrle3.c   (English version of RLE3 encoding)
                         +--> codrle4.c   (English version of RLE4 encoding)
                         +--> codhuff.c   (English version of Huffman encoding)
                         +--> codlzw.c    (English version of LZW encoding)
                         +--> dcodrle1.c  (English version of RLE1 decoding)
                         +--> dcodrle2.c  (English version of RLE2 decoding)
                         +--> dcodrle3.c  (English version of RLE3 decoding)
                         +--> dcodrle4.c  (English version of RLE4 decoding)
                         +--> dcodhuff.c  (English version of Huffman decoding)
                         +--> dcodlzw.c   (English version of LZW decoding)