Weighted median based colour filter array demosaicking

When a single image sensor is used to capture a colour image, only one colour at each pixel location is acquired. Colour filter array demosaicking is an interpolation process to evaluate those missing colour pixel values. However, an interpolation process will often blur a sharp edge. In our paper, four interpolants are first estimated using cubic interpolation in four opposite directions so that no interpolation is carried out across an edge. A weighted median filter is then used to act as a classifier for the determination of an output from the four interpolants to preserve edges. It has been shown that our proposed method can preserve sharp colour edges and produce minimal colour artifacts in the output image.