Re: [9fans] PNG and APE (cntd)

[lucio@proxima.alt.za]

> I remain unconvinced that all this effort on porting libpng
> isn't wasted time.  If the current png reading code doesn't
> work, I'd rather see that improved.  Andrey and I went through
> it a year ago and made it pass all the tests in the PNG suite.

Oh, the primary target is GeoTiff and the secondary one is Graphviz.
I'm trying to produce a marked-up map of the area I live in and the
format of the maps and aerial photographs I have sourced from the
South African Surveyor General's office are in GeoTiff format.

Since I needed zlib and libjpeg and GD wants libpng, it has been
instructive to cut my teeth on npng.  I had a recollection that png(1)
did not do 24-bit images, but no proof, so I went ahead and started
from a different end.

I did discover that PNG isn't widely used, that the patent on LZW has
expired and that I have plenty left to learn about graphics (thanks to
all contributors, not least forsyth for the Microsoft papers - td's
contribution does not need mention on this forum).

As for Breadpng(), there's no ways I'm going to study the actual
on-disk representation of PNG or any of the other formats without very
sound reason.  Life is way too short :-)

That does not mean that I do not appreciate the value of doing it, or
that I am not grateful to those who took it upon themselves to do it,
of course.  Philosophically, I'm at odds with the Plan 9 approach, but
it's a pragmatic decision.

++L