Image demosaicking (or demosaicing) is the problem of interpolating full color information on an image where only one color component is known at each pixel. This problem arises in digital cameras: most cameras use a color filter array and a 2D array of light sensors such that either red, green, or blue light is measured at each pixel location.
Many methods have been proposed for solving the demosaicking problem. The following articles provide description, online demos, and source code for a few demosaicking methods:
See also my works on interpolation.