pngcheck version 1.99.2 of 18 November 1999

This "semi-official" version of pngcheck (i.e., not produced by Alexander
or Andreas) contains several enhancements beyond the stock version 1.98,
which was the last release before I took over:  zlib capability (to be able
to print out the line filters for each line of the image); information on
the compression factor of the image (expressed as a percentage, where 0% is
no compression and 100% would be total compression--note that this can be
negative since it counts PNG's chunk overhead against the compression factor);
extended support for printing palettes (includes transparency info and histo-
grams now); partial support for MNG streams conforming to Draft 64 or later;
and support for MSVC compilation under Win32.  It also contains a fix from
Tom Lane for a bug in the pHYs-reporting code.

Improved support for MNG and JNG, as well as support for PNG's pCAL and iTXt
chunks and for some vendor-specific chunks, is coming relatively soon, but I
won't make any promises as to when.  In the near term, I'm temporarily handing
off the code to Eric Raymond, who is going to extend pngcheck into a full PNG
"compiler"--that is, it will be able to convert a text description of an image
to a true PNG, and vice versa.

Support for EBCDIC-based systems is on the way, too.  DOS/Win32 wildcards
should already be supported as of this release, at least in the distributed
binaries.

See http://www.libpng.org/pub/png/apps/pngcheck.html for updates.

Greg Roelofs
newt@pobox.com