Color demosaicing with contour stencils

Demosaicing is the problem where, given a color image that has been subsampled by a color filter array, to interpolate the complete color information at each pixel. Many demosaicing methods adapt the interpolation according to estimated edge orientations. However, while the accuracy of these orientations is important for success, they are difficult to estimate from the mosaiced image. This paper extends contour stencils, a method for estimating image contours based on total variation along curves, to estimating contour orientations directly on mosaiced images. A method for demosaicing using these contour orientation estimates is proposed and compared with existing methods. The proposed demosaicing is performed as an energy minimization, using a graph regularization adapted according to the orientation estimates.