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Monitor Gamma Correction

In order to display a series of images on the monitor in a linear scale, an inverse monitor gamma transformation must be applied to the images. This requires the monitor gamma function.

The exponential gamma function was used.

outputValue = 255*((inputValue)/256).^(gamma)

Using the matlab script Gamma.m an image was displayed showing a gray patch and black and white checker board. The gamma can be determined by adjusting the gray patch to match the black and white checker board. This matchs gives the half point on the gamma function and can be used to determine the gamma. A gray patch of 160 was required on the monitor. This gives a gamma of 1.495.

Here is the resulting inverse monitor gamma function.

trek@alumni.stanford.edu
lihui@leland.stanford.edu