Tone mapping

Posted on August 28th, 2008 by julien

Just a little test to point out that the tonemapping works. This tonemapping is special, it is reequilibrating the contrast/luminosity over all the image. Some people may dislike the corrected image as it looks unnatural however.

Here are the steps followed by the algorithm:

Convert input RGB image to YCbCr color space.

Compute the gradient of the luminance channel.

Calculate a new luminance channel by solving the partial differential equation of Poisson. This is done using a Gauss-Seidel solver at the moment, and this is why it doesn't converge at speeds that are sufficient for realtime use.

Convert back to RGB color space and write as jpeg.