Re: amaya, transparent indexed-color PNGs

On Feb 12,  3:22pm, Glenn Randers-Pehrson ARL-WMRD-TED-TIB wrote:


> In a PNG, with
>
>      PLTE 0 0 0   0 0 0    255 255 0
>      tRNS 0
>
> Amaya treats both of the 0 0 0 colors as transparent.  Evidently it
> promotes indexed pixels and the tRNS chunk, and then makes everything
> with 0 0 0 pixels transparent.

Oops.

> That's incorrect.  Transparency is by index values, not by colors, in
> indexed-color PNGs.

Right. Presumably this is handled by the application and not by libpng,
because Amaya uses zlib and libpng. Has anyone looked over the source?

This may be related to Amaya 0.95b using an 8bit indexed internal
color model.

> Also, Amaya doesn't seem to understand the < object > tag.

Correct, the released version does not implement the object tag yet.


-- 
Chris Lilley, W3C                          [ http://www.w3.org/ ]
Graphics and Fonts Guy            The World Wide Web Consortium
http://www.w3.org/people/chris/              INRIA,  Projet W3C
chris@w3.org                       2004 Rt des Lucioles / BP 93
+33 (0)4 93 65 79 87       06902 Sophia Antipolis Cedex, France

Received on Wednesday, 12 February 1997 21:55:59 UTC