Directional Color Filter Array interpolation based on multiscale color gradients

Single sensor digital cameras capture one color value for every pixel location. The remaining two color channel values need to be estimated to obtain a complete color image. This process is called demosaicing or Color Filter Array (CFA) interpolation. We propose a directional approach to the CFA interpolation problem that makes use of multiscale color gradients. The relationship between color gradients on different scales is used to generate signals in vertical and horizontal directions. We determine how much each direction should contribute to the green channel interpolation based on these signals. The proposed method is easy to implement since it is noniterative and threshold free. Experiments on test images show that it offers superior objective and subjective interpolation quality.