What is the difference between the white balance and the color constancy?

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[mahmoudnafifi]

Hi, thanks for your question.

Color constancy aims at rendering original object colors regardless of scene lighting conditions. The white balance goal, on the other hand, is to render achromatic colors (i.e., greyish) properly. White balance is commonly assumed to achieve the goal of color constancy, but this is just an assumption. Because it is typically implemented by a diagonal correction (i.e., a linear scale of each color channel independently), which apparently can't fix all colors perfectly. Hope you find this helpful.