A simple example of global tone mapping filter is formula_1 where "V"in is the luminance of the original pixel and "V"out is the luminance of the filtered pixel. This function will map the luminance "V"in in the domain formula_2 to a displayable output range of formula_3 While this filter provides a decent contrast for parts of the image with low luminance (particularly when ), parts of the image with higher luminance will get increasingly lower contrast as the luminance of the filtered image goes to 1.