If the constraint of —quality is that it is always 0-100, then that is
going to be hard to map and would lead to confusion(i.e. All other
applications would use a different slider then oiio). Is it possible to
make the quality slider more contextual to the compression rather then
normalizing it to always be 0-100?
On Tue, Sep 20, 2016 at 11:49 PM, Larry Gritz <l...@larrygritz.com> wrote:
> 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
> > 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
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> Larry Gritz
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