Combine -> Images Different EV's -> hdr format. >1.0f

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yellow
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Combine -> Images Different EV's -> hdr format. >1.0f

Post by yellow »

hi

I'm piping raw 48bit RGB video frames from avisynth to linear EXR via IM successfully thanks to help on this forum. :-) But I now have a new twist to the process which is videos shot with interleaved exposures of set EV within the video frames ie: dark frame -> light frame -> dark frame etc. Dark to Light is user set before capture 1EV to 5EV. The camera basically jumps ISO between frames, capturing a progressive stream of alternating exposures.

The final output I'd like to produce is a hdr image format, floating point, unscaled which encompasses the extent of the exposure range of EV's without normalising 0.0 - 1.0 ie: perhaps take dark image as 0.0 - 1.0 and bright image data 1.0 - 2.0. Now I think that's what I need to do, more than happy to be told this is wrong approach, wrong theory. :-)

The hdr images would then be manually tonemapped in an external application. Image formats supported would be amongst exr, tiff, ppm in order of preference.

As a starting point for discussion I have this on the CLI:
wine ./avs2yuv.exe -raw "avisynthscript.avs" -o - | convert -limit memory 500MiB -limit map 1GiB -size 1920x1088 -depth 16 -define quantum:format=floating-point -define quantum:scale=65536.0 -profile Linear_sRGB_D65.icc -set colorspace RGB -colorspace RGB rgb:- "IM_%06d.exr"
Last query, I've managed to add color profile info to the output as it goes through the chain, but is it possible to add a simple exif tag for the EV value in similarly for use with enfuse, that reads the exif EV tag for a alternative approach of two separate images for enfusing rather than one exr holding both exposures.
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