[Zlib-devel] Re: [png-implement] Libpng-1.2.2rc1 and libpng-1.0.13rc1

[Mark Adler]

On Wednesday, April 10, 2002, at 08:54  AM, Greg Roelofs wrote:
> It appears that memLevels 7-9 have an identical effect on Huffman-only
> compression,

That would be expected for small files.  The memLevel variation for 
Huffman-only coding can only manifest if the file is long enough or the 
blocks short  enough for the file to be broken up into more than one 
block.  In this case, that doesn't happen until the blocks are 4K or 
less.

> However, I did see at least one case where an intermediate level was
> best:
>
>    2122340:  5  2  3,0,0,2,1,2,3,0   5754  <--

This is telling me that that particular example is changing the 
distribution of its bytes approximately every 2K bytes.

mark