We present a color filter array interpolation algorithm to provide the missing colors associated with the commonly used Bayer pattern in digital still camera systems. The developed algorithm utilizes color correlation and directional derivative attributes of neighboring color pixels and is thus named C2D2. The main advantage of this algorithm is that it requires no user-defined parameter, as is the case in many edge-adaptive color filter array interpolation algorithms. Both an objective and subjective comparison are carried out with two other popular edge-adaptive algorithms. The results indicate that this algorithm consistently generates lower mean-squared interpolation errors in the RGB and L*a*b* color spaces.
Nasser Kehtarnavaz, Hyukjoon Oh, Youngjun F. Yoo, "Color filter array interpolation using color correlations and directional derivatives," J. Electron. Imag. 12(4) (1 October 2003)