Mosaic images are captured by a single charge-coupled device/complementary metal-oxide-semiconductor (CCD/CMOS) sensor with the Bayer color filter array. We present a new qualityeffective zooming algorithm for mosaic images. First, based on adaptive heterogeneity projection masks and Sobel- and luminanceestimation-based masks, more accurate gradient information is extracted from the mosaic image directly. According to the extracted gradient information, the mosaic green G channel is first zoomed. To reduce color artifacts, instead of directly moving the original red R value to its right position and the blue B value to its lower position, the color difference interpolation is utilized to expand the G-R and G-B color difference values. Finally, the zoomed mosaic R and B channels can be constructed using the zoomed G channel and the two expanded color difference values; afterward, the zoomed mosaic image is obtained. Based on 24 popular test mosaic images, experimental results demonstrat...