[Zlib-devel] Proposed code change

[Greg Roelofs]

> On Saturday 28 October 2006 7:11 pm, Mark Adler wrote:
> > On Oct 28, 2006, at 7:04 AM, Steve Snyder wrote:
> > > While profiling the display of large PNG graphics in Firefox recently
> >
> > I'd like to add these large PNG graphics to my suite for performance
> > testing.  If they're available, please let me know where I can fetch
> > them from.  Thanks.

> Look here for large PNG files:  
> http://ftp.arl.mil/ftp/historic-computers/png/

> I'm particularly fond of cyber173.png (12MB), cyber7600.png (11MB) and the 
> behemoth pdp11,70.png (20MB !).

Is it just me, or is there some corruption in the middle of cyber7600.png?
That is, the zlib data are self-consistent, but the pixels are obviously
wrong.  (Did Glenn have anything to do with these?)

> If your interest goes beyond sheer size, check out  
> http://www.libpng.org/pub/png/ for some fancier (progressive, layered, 
> alpha-blended, etc.) graphics.

I have some other big test images, too:

2693372 Jul 29  2004 16million-hilbert-curve.png   4096 x 4096, 24-bit RGB
  59852 Jun 30  1998 16million-pschmidt.png        4096 x 4096, 24-bit RGB
 199338 Oct 30  2000 DavesLine-12078x5593-bw.png   12078 x 5593, 1-bit colormap
4378822 Jun 12  2002 aw32-10x6-sharpen50.png       5400 x 3240, 24-bit RGB
1975679 Oct  4  2003 earthlights-dmsp-big-PIA02991.png 2400 x 1200, 24-bit RGB
  21198 Nov  3  1998 ecg-8192.png                  8192 x 276, 8-bit grayscale
1568709 Mar 13  1999 mars_10000-crb.png            10000 x 10000, 8-bit colormap
 172283 Mar 12  1999 oss-poster-big-crb.png        3660 x 2153, 8-bit colormap
4173459 Mar  8  2005 sfbay-2-tiles_jpeg-rgba.png   1564 x 2207, 24-bit RGB

I think only the pschmidt one is on the web site.  (The mars one is
actually a 1024x1024 image, I think, that apparently was blown up
to 10000x10000 via simple pixel replication.  Most super-pixels are
10x10, but some are 9x10 or 10x9, and I suppose there are a handful
of 9x9 ones in there somewhere...)

I also have this set, which is notable because it's early (mostly
21 Aug 1995) and (probably) not generated using zlib:

3491026 Jan 23  2005 photodex-test-images.zip

That archive is on either the web site or the ftp site (somewhere),
but I don't recall where offhand.

Greg

P.S.  You can also find some 16 Mpix JPEGs on flickr that can be converted
      to PNG format (or deflated TIFF), if you want to create your own test
      suite...