вт, 7 нояб. 2023 г., 21:46 Andrew Randrianasulu <[email protected]>:
oiiotool --stats -v /dev/shm/1.exr Reading /dev/shm/1.exr /dev/shm/1.exr : 4096 x 2048, 3 channel, float openexr channel list: R, G, B chromaticities: 0.639999, 0.33001, 0.300004, 0.600003, 0.150002, 0.0599972, 0.3127, 0.329 compression: "zip" PixelAspectRatio: 1 screenWindowCenter: 0, 0 screenWindowWidth: 1 oiio:ColorSpace: "Linear" oiio:subimages: 1 Stats Min: 0.005371 0.006256 0.006348 (float) Stats Max: 117.000000 106.500000 104.500000 (float) Stats Avg: 0.746420 0.699325 0.674529 (float) Stats StdDev: 3.869811 3.841790 3.957525 (float) Stats NanCount: 0 0 0 Stats InfCount: 0 0 0 Stats FiniteCount: 8388608 8388608 8388608 Constant: No Monochrome: No
this is for gimp exported EXR
cingg exported tiff says:
Reading /dev/shm/1.tif /dev/shm/1.tif : 4096 x 2048, 4 channel, float tiff channel list: R, G, B, A compression: "zip" Orientation: 1 (normal) planarconfig: "contig" oiio:BitsPerSample: 32 tiff:Compression: 32946 tiff:PhotometricInterpretation: 2
tiff:PlanarConfiguration: 1
tiff:RowsPerStrip: 1
tiff:UnassociatedAlpha: 1
Stats Min: 0.265371 0.266256 0.266348 1.000000 (float)
Stats Max: 1.000000 1.000000 1.000000 1.000000 (float)
Stats Avg: 0.630706 0.600794 0.582030 1.000000 (float)
Stats StdDev: 0.221808 0.214916 0.202718 0.000000 (float)
Stats NanCount: 0 0 0 0 Stats InfCount: 0 0 0 0 Stats FiniteCount: 8388608 8388608 8388608 8388608
Constant: No Monochrome: No
====
example usage from
https://openimageio.readthedocs.io/en/latest/oiiotool.html
wow, so oiiotool in itself a bit like imagemagick :)
might make preparing some image sequences easier ...
also, guess we better to note in manual that even if cingg outputs fp32 exr/tiff values there are normalized to 0-1.0f as far as we can see.
https://docs.krita.org/en/general_concepts/colors/bit_depth.html Also, Krita docs says about 16 bit per ch integer vs 32bit per channel fp without values over 1.0f ==== 16bit per channel One step up from 8bit, 16bit per channel allows for colors that can’t be displayed by the screen. However, due to this, you are more likely to have smoother gradients. Sometimes known as “Deep Color”. This color depth type doesn’t have negative values possible, so it is 16bit precision, meaning that you have 65536 values per channel. ===== 32bit float Similar to 16bit float but with even higher precision. The native color depth of OpenColor IO, and thus faster than 16bit float in HDR images, if not heavier. Because of the nature of floating point type variables, 32bit float is roughly equal to 23-24 bits of precision per channel (16777216 values per channel in the 0-1 range), but with a much wider range (it can go far above 1), necessary for HDR/Scene-referred values. It is also known as ‘single floating point’. ==== so I guess this mean even WITHOUT going above 1.0 fp output format still more accurate than 16bit per channel integer tiff or png. But I am bad at math for PROVING it. :(