Abstract: In this article we present a lossy frame-buffer compression format, suitable for existing commodity GPUs and APIs. Our compression scheme allows a full-color image to be directly rasterized using only two color channels at each pixel, instead of three, thus reducing both the consumed storage space and bandwidth during the rendering process. Exploiting the fact that the human visual system is more sensitive to fine spatial variations of luminance than of chrominance, the rasterizer generates fragments in the YCoCg color space and directly stores the chrominance channels at a lower resolution using a mosaic pattern. When reading from the buffer, a simple and efficient edge-directed reconstruction filter provides a very precise estimation of the original uncompressed values. We demonstrate that the quality loss from our method is negligible, while the bandwidth reduction results in a sizable increase in the fill rate of the GPU rasterizer.