Histogram equalization of 24-bit color images in the color difference (C-Y) color space
Arthur R. Weeks · Journal of Electronic Imaging · 1995
We describe a method of enhancing color images by applying histogram equalization to the saturation component in the color difference (C-Y) color space. When histogram equalization is applied to the saturation component of a 24-bit image, the transform often leads to red, green, and blue components that exceed the realizable RGB intensities. The histogram equalization algorithm presented reduces this problem by taking into account the relationship that exists between luminance and saturation and how the luminance value limits the range of possible saturations. This method also retains a more uniform distribution of color saturation once the components are transformed back into the RGB space. This is important for images that contain high-luminance, low-saturation features.