Branches
Comments
[»]
Just to make things clear
by Idanso - Aug 18th 2000 07:48:47
I got a few responses regarding similarity between the description of
the algorithm to Huffman algorithm. I doubt If many of those critics took
the time to look at the PHP source however
In order to make a few things clear, I don't think there is any
similarity to Huffman, maybe at the very basic concept level, but not in
the algorithm itself(Huffman uses B-Trees, And can compress files that use
even 99% of the ASCII table. the last time i checked, BitComp did not use
B-Trees, and requires files to use less than 50% of the ascii table for
minimal compression), and not in the compression ratio
As a proof, i downloaded Huffman implementation from the internet(which
came with the source). I compressed a sample file using both Huffman and
Bitcomp. results are as follows
- Original : 15096 bytes
- BitComp : 13209 bytes
- Huffman : 8973 bytes
So, as you can see, BitComp is not huffman. the sample file used 86/256
from the ascii table, that means BitComp encoded it in 7-bits. Huffman
definatly used some other method
This does not mean BitComp is a poor compression method however, As not
all features(like LZ encapsulation) are currently implemented, so while(as
i claimed on the web site) it is currently easily bypassed by LZ7?
algorithms, it doesn't mean it will not be improved in the near future
Hope that made a few things clear
idan
[reply]
[top]
[»]
Hmm.
by Dan Egnor - Aug 17th 2000 18:12:22
Someone needs to explain Huffman coding to this person, and point out that
any respectable file compression utility ('compress', gzip, bzip2, etc.)
will certainly achieve the basic symbol-space compression
"BitComp" touts as a "new compression technique".
[reply]
[top]
|
