Color Recognition of real color

I'd like to find out the "real" color of an object in an image automtacially. For example: If I take a photo from a wall, I would like to reproduce the color of the wall so that I can paint another wall with the same color. The ima开发者_运维知识库ge taken will include a reference object from which the programm knows the exact color data. For example a coke can.

I assume the following:

• Knowing the exact color value of the coke can, helps me to determine the light temperature of the image
• After determining the light temperarure of the image the programm would be able to determine the exact and correct color of the wall. Independent of the lighting of the scene.

Is my assumption correct and are there any libraries available which helps me to a accomplish this task?

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You may also need to assume the following:

• There is only one type of lamp in the room. E.g. the wall and the coke may be lit by two different light sources.
• The spectral distribution of the lamp. It is easy to model incandescents, but LED and CFL may vary with which brand is used.
• The spectral response of the camera. Some cameras do not register light in the low and high wavelengths.

Basically, you need to read about metamerism.

You may find yourself in a situation where if you were to take a picture of the two walls, they have the same color. But if you look at them in person, they have distinct colors.