Novel quality-effective zooming algorithm for color filter array

bstract. Mosaic images are captured by a single charge-coupled evice/complementary metal-oxide-semiconductor (CCD/CMOS) ensor with the Bayer color filter array. We present a new qualityffective zooming algorithm for mosaic images. First, based on daptive heterogeneity projection masks and Sobeland luminancestimation-based masks, more accurate gradient information is exracted from the mosaic image directly. According to the extracted radient information, the mosaic green G channel is first zoomed. o reduce color artifacts, instead of directly moving the original red R value to its right position and the blue B value to its lower osition, the color difference interpolation is utilized to expand the -R and G-B color difference values. Finally, the zoomed mosaic R nd B channels can be constructed using the zoomed G channel nd the two expanded color difference values; afterward, the oomed mosaic image is obtained. Based on 24 popular test mosaic mages, experimental results demonstrate that the proposed zoomng algorithm has more than 1.79 dB quality improvement when ompared with two previous zooming algorithms, one by Battiato et l. (2002) and the other by Lukac et al. (2005). © 2010 SPIE and S&T. DOI: 10.1117/1.3302126