8bit to 32bit EXR?

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pegot
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Joined: Mon Nov 07, 2011 3:44 am

I try to use 32bit exr files for displacement whenever possible, as generated by my texturing programs.

I am wondering if the following make sense. If one has a very high pixel size 8bit image that will be resized by 75% before use as a displacement map, would it be beneficial to convert it to 32bit before resizing and then exporting as an exr?

Would the data from the original larger pixel size image be retained but with substantial file size and memory savings?
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elsksa
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Hi pegot, I believe Octane will feature more texture optimization at its core. If I am not mistaken, it is in their roadmap. This, is the ideal way of handling texture data and Octane currently has a useful compression method built-in. Both the Surfacers/Texturing Department and the renderer have to do optimizations.

I am not sure to follow regarding the bit-depth. Are you, sometimes, exporting and using 8-bit displacement map? If yes, they will yields in artifact results and should be avoided. The displacement map should ideally be 32-bit floating point and single-channel with a linear transfer function specification, preferably as an OpenEXR file (being the only supported file that features 32-bit floating-point).

Resolution can be reduced - bit-depth should be left 32-bit and last but not least, an 8-bit to 32-bit "conversion" will not bring back data from the 32-bit original file. 8-bit would imply an integer file format, such as JPG/PNG since EXR does not support it, and these file format are strongly not recommended, in particular PNG due to its integer nature and bad performance.
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