Edge-adaptive color interpolation algorithm for progressive scan charge-coupled device image sensors

Yonsei UniversityDepartment of Electrical & ElectronicEngineering134 Shinchon, Seodaemun-KuSeoul, KoreaE-mail: mkang@yonsei.ac.krAbstract. The color interpolation scheme can play an important role inovercoming the physical limitation of CCD image sensors and in increas-ing the resolution of color signals, while most conventional approachesresult in blurred edges and false color artifacts. We propose an improvededge-adaptive color interpolation scheme for a progressive scan CCDimage sensor with an RGB color filter array. The proposed edge indicatorfunction utilizes not only the within-channel correlation, but also thecross-channel correlation, and reflects the edge characteristics of an im-age adaptively. The color components unavailable at each channel areinterpolated along the edge direction, not across the edges, so that alias-ing artifacts are suppressed. Furthermore, we eliminate false color arti-facts resulting from the color image formation model in the edge-adaptive color interpolation scheme by adopting the switching algorithmbased on the color edge detection. Simulation results of the proposedalgorithm indicate that the improved edge-adaptive color interpolationscheme produces results that are quantitatively better and visually morepleasing than those achieved by conventional approaches.