Re: reversable, but not 1D color transforms in config.ocio


Sean Cooper <se...@...>
 

L* is inherently logarithmic, so perhaps you could use L* it's self as the shaper here. But I think the inherently negative a*b* values will make this effort futile, unless there is an alternative all positive formulation of L*a*b*, but that would be a bit odd.

On Fri, Feb 3, 2017 at 10:52 AM, Andrew Wood <andre...@...> wrote:
Looking at my values closer, looks like you are probably right.  My input image is 0 to 1 linear, so I wasn't using a shaper.  However, when I get to LAB space, there are negative values, which would explain why its all messed up going back to rgb right afterwards.

But what shaper would even make sense here?  My head hurts trying to think about the a*b* components going through a log curve or something. That doesn't really make sense, does it?



On Thursday, February 2, 2017 at 6:41:59 PM UTC-8, Troy James Sobotka wrote:


On Thu, Feb 2, 2017, 7:32 PM Andrew Wood <andr...@...> wrote:
Unfortunately it just seems too lossy (esp in dark areas) for an unsharpening pass.

That screams bad shaper to me. What are you using for a shaper here?

With respect,
TJS

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