(mgp-users 00563) Re: [Q] transparent png's again

[Christopher Drexler <drexler@informatik.uni-erlangen.de>]

Dear List,

On Thu, May 17, 2001 at 02:03:20AM +0900, Christopher Drexler wrote:
> 
> Now I tracked to the problem down to grayscale PNG's. Color PNG's
> (regardless of 4 or 8 Bit) are displayed correctly but not 1- or 8-bit
> grayscale PNG's.
> 

I forgot to mention that I tried it with imlib support and without.
We work with Linux SuSE 7.0 which ships imlib-1.9.8.1 and
libpng-2.1.0.6. I also tried the cvs tree (1.08) and the 1.07a with the
'transparent png' patch. All versions of mgp were compiled by myself because
the distributed mgp does not support png at all.

I "solved" the problem by using imlib support, which displays color png's
correctly, and adding the native mgp pbm-support before the imlib handler
in "imagetypes.c".

Now I can use pgm for transparent graylevel images und png for transparent
color images :-). 

I also moved the 'image_set_color' call, which is responsible for the magic
transparent background setting for ps files, from 'image_load_ps' to
'image_load' so that all pgm's are displayed with transparent background,
not only those automatically generated from ps files. 

I don't know the influence on other image types as these are handled by
imlib and not by this function anymore. Maybe the author can give me some
hints here. 

If someone is iterested in the patches I can post them on the list.

Bye
Chris

-- 
Dipl.-Inf. Christopher Drexler, Lehrst.f. Mustererkennung _    __  __ ___ 
Institut f. Informatik, Universitaet Erlangen-Nuernberg  | |  |  \/  | __|
WWW : http://www5.informatik.uni-erlangen.de/~drexler  	 | |__| |\/| | _| 
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