how can I get the right RGB values from a HDR image ?
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Hi everyone Im working on HDR image analysis. I use terminal and radiance software to get the RGB value as a text in mac book and then work on them with matlab. but I have noticed that even for white area in the photo RGB values are (17, 18, 16)(or number in this range). what color space is it using ? or what is wrong with this conversion ? next question is what is the code to get the RGB value for a HDR image in Matlab ? Thanks !
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Image Analyst
2016-12-19
Those numbers describe a dark gray color. White values are usually brighter than 200 or so. I've never heard of "terminal and radiance software" so I can't really say what it's doing. And there is no "right" values for RGB for HDR images. Two points could have similar RGB but have vastly different radiances. For example, in an image of your desk and also looking out the window, the sheet of paper on your desk may have an illuminance of 500 lux but the white car that you can see through the window has an illuminance of 20,000 lux, and yet they both might appear in the image with an RGB of (200,200,200) or whatever. So you can't really say that any object in your scene has a "right" or "correct" range of RGB values. I mean the whole concept of HDR goes against that - HDR is meant to adjust the RGB so that everything looks good despite vastly different brightnesses of the subject, far more than a single exposure can handle.
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