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[Openexr-devel] DWA compression
From: |
Larry Gritz |
Subject: |
[Openexr-devel] DWA compression |
Date: |
Sat, 16 Aug 2014 23:07:39 -0700 |
The new compression modes are really great, thanks. I've been playing around
with it and it performs very well, great compression while retaining visual
quality.
But the numbers are confusing. Apologies if I missed prior discussion of this
point, but does anybody have an explanation of what the value means? I
understand the basics -- higher is more compressed, below 100 gives nearly
perfect visual fidelity -- but maybe because the scale is unbounded and highly
nonlinear, I haven't been able to come up with an easy-to-explain description.
In contrast, the 1-100 scale for JPEG quality has a more intuitive feel that,
while still not linear, seems to be no trouble to wrap one's mind around (maybe
because it reminds us of percentages?) and is much more amenable to putting
into a UI slider. I'd love to find an equation that would map an intuitive 0-1
or 0-100 scale inside an app to the dwaCompressionLevel in an analogous way.
--
Larry Gritz
address@hidden