Demosaicking with adaptive reference range selection

Abstract

Image demosaicking is a method of reconstructing an RGB image from a Bayer pattern, which is required when color information is lacking because a single charge-coupled device is used during the image extraction process of a digital camera. There are many restrictions on the reconstruction of a Bayer image to an RGB image. Given that each pixel contains only one-color information, artifacts, such as false color or the zipper effect, may occur at the edges, which can arise as a result of significant differences in brightness and color change. We propose a demosaicking method for adaptively selecting the reference range of color difference to obtain reliable information from texture regions and reconstructing into the RGB image. In particular, we determine the adaptive weight and reference range for four directions, east (E), west (W), south (S), and north (N), to improve the reliability of the color pixel obtained by a color difference estimation using guided filtering applied on residuals. In our experiment, we compare the results of the proposed method for the Kodak and IMAX datasets with those of nine demosaicking methods. The proposed method shows similar or improved results in terms of the color peak signal-to-noise ratio. In addition, compared to other methods, the visual quality improved by reducing residual artifacts.