[This is the original Amiga README for pngcheck 1.99.3, lightly edited to
 remove version-specific and/or redundant info.]


Amiga port of pngcheck compiled by Simon N Goodwin, July 2003
-------------------------------------------------------------

PNG is a Portable Network Graphics files format designed to
address the flaws of GIF. It has better compression, support
for images with more than 256 colours, and no licence fees.

This utility checks the integrity of a PNG file and optionally
extracts information from it such as the colour format, palette
contents, and embedded text identification strings.

It was compiled with SAS C for all Amigas at the request of the
maintainer Greg Roelofs, whose readme for the source follows. I
volunteered for this after spotting that the link to Aminet on the
pngcheck home page was broken, and sending the correction to Greg.
He pointed out that pngcheck has since been updated (the latest
source is about three times the size of that for the old Aminet
release) and asked me to compile the latest one for Amiga users.

Simon Goodwin, ami@studio.co.uk



Limitations of the Amiga port
-----------------------------

The optional ZLIB capability is not implemented on the Amiga version.

Wildcards are not supported (as they are implemented by the shell on
Unix/Linux, but not in AmigaDOS) but can be simulated with the Amiga
Shell LIST .. LFORMAT facility, e.g:

    list cbig:Graphix/#?.png lformat="pngcheck %P%N" >ram:temp
    type ram:temp

pngcheck cbig:Graphix/ZX80A.PNG
pngcheck cbig:Graphix/ZX80A16.PNG
pngcheck cbig:Graphix/ZX80A32.PNG
pngcheck cbig:Graphix/ZX80A8.PNG
pngcheck cbig:Graphix/ZX80grey.PNG

    execute ram:temp

OK: cbig:Graphix/ZX80A.PNG (656x480, 8-bit colormap, non-interlaced, 41.5%).
OK: cbig:Graphix/ZX80A16.PNG (656x480, 4-bit colormap, non-interlaced, 75.3%).
OK: cbig:Graphix/ZX80A32.PNG (656x480, 8-bit colormap, non-interlaced, 81.1%).
OK: cbig:Graphix/ZX80A8.PNG (656x480, 4-bit colormap, non-interlaced, 72.5%).
OK: cbig:Graphix/ZX80grey.PNG (656x480, 8-bit colormap, non-interlaced, 41.3%).

A Amiga shell script, pngcheck_all, is included to simplify this for you:

    pngcheck_all cbig:Graphix/ZX80A#?.png

OK: cbig:Graphix/ZX80A.PNG (656x480, 8-bit colormap, non-interlaced, 41.5%).
OK: cbig:Graphix/ZX80A16.PNG (656x480, 4-bit colormap, non-interlaced, 75.3%).
OK: cbig:Graphix/ZX80A32.PNG (656x480, 8-bit colormap, non-interlaced, 81.1%).
OK: cbig:Graphix/ZX80A8.PNG (656x480, 4-bit colormap, non-interlaced, 72.5%).

Note: optional parameters (-t, -v etc) are not yet supported by this script.



Compilation notes
-----------------

The source was compiled without alteration using this AmigaDOS command:

    sc data=far code=far opt lib lib:scm.lib pngcheck.c

If you have the supplied scoptions file in the current directory with
the source you can simplify this to:

    sc pngcheck.c

The compiled version uses generic 68000 code. This makes it 516 bytes
longer and marginally slower on some CPUs than a 32 bit optimised
version, but means it is suitable for any Amiga. The 68020 optimised
version is available on request from Simon Goodwin, ami@studio.co.uk
If you have a suitable compiler (SAS was used for 1.99, and 1.97 was
compiled with GCC) you can easily build your own.
