I want to measure the relative and absolute luminace of hdr images by using matlab. I read several papers and I know there are many software generating this (photosphere, photolux, aftab). However, for my reaserch, I should write a code to do that conversion.
Well , I am sure you know this that RGB values => reflectance that is based on material property and light quality !
So , using a Sensor (CMOS or CCD) they convert a reflectance value or luminance and chrominance are capture in radiometric domain.
Now , photo vs radio conversion is wavelength based or color are you call it. So taking a raw RGB (24-bit) to convert HDR (32 bit) format you need to look at the decoupling of luma and chroma ...
Well , I am sure you know this that RGB values => reflectance that is based on material property and light quality !
So , using a Sensor (CMOS or CCD) they convert a reflectance value or luminance and chrominance are capture in radiometric domain.
Now , photo vs radio conversion is wavelength based or color are you call it. So taking a raw RGB (24-bit) to convert HDR (32 bit) format you need to look at the decoupling of luma and chroma ...
well, I have some HDR imges. I extracted the R G B values by Matlab. Then, I calculated the relative luminance based on the RBG values and using the equation (Luminance = (0.2126 × red) + (0.7152 × green) + (0.0722 × blue)). Now, I want to scale the relative luminance to absolute luminance (cd/m²) which I do not know how I should do this conversion.
I hope this link helps, it requires color space conversion
https://pdfs.semanticscholar.org/dd3e/447e28a12fbbaf7977a046d2cebc28ecce8b.pdf
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