Hello. I am trying to calculate luminance values from Radiance RGBE

values. Somehow, I am not getting good results.

For example, at a certain pixel, the RGBE values are:

R = 128; G = 137; B = 165; E = 129

which is (1.00 1.07 1.29) in RGB values.

The luminance value computation is given by the formula:

luminance = 179 * (0.265*R + 0.670*G + 0.065*B)

With the above RGB values, I calculate luminance as 190.77 (which is

too low) and luminance inquiry in ximage gives 3181 cd/m2 (which makes

lots of sense) for the same pixel. Obviously, I am missing something here.

I would appreciate any help in calculating luminance values from RGBE

data. Thank you.

Mehlika Inanici

University of Michigan o

Taubman College of Architecture + Urban Planning o

Office: 2224 B |\ o

2000 Bonisteel Boulevard | \ o

Ann Arbor, Michigan |\ / .\ o

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http://www.umich.edu/~inanici | /

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