A novel approach of image compression in digital cameras with a Bayer color filter array

Abstract

We propose a new approach for image compression in digital cameras, where the goal is to achieve better quality at a given rate by using the characteristics of a Bayer color filter array. Most digital cameras produce color images by using one CCD plate and each pixel in an image has only one color component, so an interpolation method is needed to produce a full color image. After finishing an image processing stage, in order to reduce the memory requirements of the camera, a lossless or lossy compression stage, using a coder such as JPEG, often follows. Before decreasing redundancy in a compression stage, redundancy is increased in an interpolation stage. We propose an algorithm for image compression, in which the order of the compression and interpolation stages is reversed to avoid increasing redundancy before compression. We introduce the image transform to compress uninterpolated images with JPEG. Our simulations show that the result of our algorithm is better than conventional methods for all compression ranges. This proposed algorithm provides not only better quality but also lower complexity because the number of luminance data of our method is only half of that of conventional methods.