Yes, that’s the same thing. By accident, I sent it from the wrong email address 
initially.

-Stefan

> On 15. Jul 2017, at 01:15, Larry Gritz <[email protected]> wrote:
> 
> Sorry, I think this one was clogged in the moderation queue and just now got 
> dislodged. I believe this is from the subsequent discussion and patches which 
> have now already been merged.
> 
> 
>> On Jul 4, 2017, at 12:39 PM, Stefan Werner <[email protected] 
>> <mailto:[email protected]>> wrote:
>> 
>> Hi,
>> 
>> I ran across one texture that I can’t quite figure out how to deal with it 
>> correctly using TextureSystem. The original texture is a gray scale PNG with 
>> alpha channel, and I’m converting it with maketx. I’m trying to get that 
>> back as RGBA via the gray_to_rgb=1 option in the texture cache, but I always 
>> get the gray channel as R and the alpha channel as G, with B and A 
>> empty/default.
>> 
>> I stepped through the code, and I see that in 
>> TextureSystemImpl::fill_gray_channels(), line 848, the case for two channel 
>> input files only does the conversion when spec.alpha_channel = 1. When I use 
>> TIFF for my cache file format, spec.alpha_channel is -1, when I use OpenEXR 
>> as cache file format, spec.alpha_channel is 0. Maketx apparently only marks 
>> TIFF as containing an alpha channel when there are 4 or more channels, see 
>> tiffoutput.cpp line 485. OpenEXR does set the channel name to alpha.
>> 
>> Is there a reason that fill_gray_channels() checks for index of the alpha 
>> channel rather than just its presence? Is there any way that I can get this 
>> texture to be read as RGBA through the texture cache?
>> 
>> Thanks,
>> Stefan
>> _______________________________________________
>> Oiio-dev mailing list
>> [email protected] <mailto:[email protected]>
>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org
> 
> --
> Larry Gritz
> [email protected] <mailto:[email protected]>
> 
> 
> 
> 
> _______________________________________________
> Oiio-dev mailing list
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