OpenDRT v0.0.80
Pre-release
This is a big change with a lot of development work compared to v0.0.75. Here is a summary of the notable new features:
Tonemap
- Replace tonemapping function with a piecewise hyperbolic compression function with power and parabolic toe compression.
See this desmos plot for details on the math.
And if you're curious about other options and a verbose history of the development, check out these posts on the acescentral thread. In particular, this one and this one. - First pass model and presets for HDR displays
Chroma Rendering
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Switch to using a "weighted vector length" norm. This allows a massive complexity reduction while preserving the nice rendering features I was trying to achieve with much more complex methods before:
- More saturated colors especially blues and reds render darker, while yellow and orange renders brighter
- Saturation boosted along the red/blue axis while keeping magenta and yellow under control
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Switch the rendering colorspace to Truelight LMS, described in Chromaticity coordinates for graphic arts based on CIE 2006 LMS with even spacing of Munsell colours by Richard Kirk.
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Apply chromatic adaptation for white-point handling as LMS scales in the rendering colorspace.
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Calculate whitepoint normalization factor based on whitepoint and output display gamut, and concatenate with other output domain scale elements
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Add inverse transform
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Completely rework and massively simplify InverseEOTF and EOTF nodes