maketx doesn't have a --quality command at all, primarily because we'd 
traditionally been using either lossless TIFF or OpenEXR for textures, and for 
neither of those did quality come into play.

But recently we added support for TIFF-with-jpeg, and OpenEXR with DWAA 
compression has since come along and looks useful, so if you think that a 
--quality flag for maketx is helpful, we can add it. 

The real problem is that quality is assumed to be 0-100, with 100 meaning 
lossless. It works well for JPEG, which is the prototypical example. But I 
wasn't sure how to make it map to the dwa compression level without being 
confusing (dwa compression is an open ended scale, and higher numbers mean more 
compression).

I'm perfectly happy to entertain requests to change it, if there's consensus. 
For example, if somebody wants to propose an intuitive and helpful mapping of 
the 0-100 scale of Quality into the appropriate dwaCompressionLevel, I think 
that might be useful.

As you've seen, you can set the compression levels for dwaa and dwab by setting 
the "openexr:dwaCompressionLevel" attribute. It's not hooked up to the 
"--quality" only because, ad just mentioned, it wasn't obvious how that mapping 
should work. 




> On Sep 20, 2016, at 3:11 PM, Deke Kincaid <dekekinc...@gmail.com> wrote:
> 
> Hi Larry
> 
> We are trying to compress EXR files in OIIO with dwaa/dwab compression but 
> currently this does not seem to directly hooked up to the --quality flag in 
> oiiotool.  No matter if you use --quality 10 or 100, the attr 
> dwaCompressionLevel key never gets set and the file is exactly the same size. 
>  
> 
> We found that we need to directly set the attr via:
> oiiotool blah.exr --ch R,G,B --croptofull --compression dwaa --attrib 
> dwaCompressionLevel 100.0 -o blah_dwa.exr
> 
> Any chance we could get this attr hooked up to the quality slider?  Also it 
> appears that maketx does not have a --quality flag either (I haven't checked 
> iconvert).
> 
> -deke
> 
> 
> _______________________________________________
> Oiio-dev mailing list
> Oiio-dev@lists.openimageio.org
> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org

--
Larry Gritz
l...@larrygritz.com


_______________________________________________
Oiio-dev mailing list
Oiio-dev@lists.openimageio.org
http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org

Reply via email to