Color filter array residual demosaicking with efficient median filter

Color images can be taken in a single or multi-sensor digital camera. A multi-sensor camera captures all the three channels of an image whereas a single sensor camera captures only a portion of the image data (ie. only one color channel in each pixel location). The process of estimating the missing two color channels, in such a raw image is called as demosaicking. We propose a new approach of applying a joint weighted median filter (JWMF) to the residual demosaicking process. This method gives a finely filtered demosaicked image which plays an important role in demosaicking to obtain an image with respect to the visual perception of human eye. Demosaicking is applied to the very commonly used Bayer color filter array (CFA). Residual demosaicking (RD) is different from the conventional color difference demosaicking in which the residuals are used to interpolate the red and blue color channels using the interpolated green as the guided image. It has been shown that the result of the proposed method preserves the edges and removes artifacts.