Single-chip digital cameras use a color filter array and subsequent interpolation strategy to produce full-color images. WHile the design of the interpolation algorithm can be grounded in traditional sampling theory, the fact that the sampled data is distributed among three different color planes adds a level of complexity. Previous ways of treating this problem were based on computationally intensive approaches, such as iteration. Such methods, while effective, cannot be implemented in todays crop of digital cameras due to the limited computing resources of the cameras and the accompanying host computers. These previous methods are usually derived from general numerical methods that do not make many assumptions about the nature of the data. Significant computational economies, without serious losses in image quality, can be achieved if it is recognized that the data is image data and some appropriate image model is assumed. To this end, the design of practical, high- quality color filter array interpolation algorithms based on a simple image model is discussed.
James E. Adams,
"Design of practical color filter array interpolation algorithms for digital cameras", Proc. SPIE 3028, Real-Time Imaging II, (3 April 1997); doi: 10.1117/12.270338; https://doi.org/10.1117/12.270338