Reduction of Colour Artifacts Using Inverse Demosaicking

Abstract

Most digital cameras use a single image sensor to capture colour images. As a result, only one colour at each pixel location is acquired. Demosaicking is a technique to estimate all the other missing colour pixel information in order to produce a full colour image, while inverse demosaicking refers to the recovery of the single image sensor values from the full colour image. Early digital cameras using primitive demosaicking algorithms to produce a full colour image have resulted in inferior quality images with colour artifacts. Generally, the removal of those artifacts is not achievable by the application of direct filtering. If we can recover the actual image sensor values from a full colour image and re-demosaic it again using state-of-the-art recently developed demosaicking algorithms, a better image can be produced without filtering. In this paper, a novel technique using wavelet transform is proposed to inverse demosaic a full colour image in order to recover the actual sensor values. It is then re-demosaicked using an advanced recently developed demosaicking method to reproduce an output image with minimal colour artifacts.