Polygon-assisted JPEG and MPEG compression of synthetic images
Marc Levoy · 1995
Recent advances in realtime image compression and decompression hardware make it possible for a high-performance graphics engine to operate as a rendering server in a networked environment.If the client is a low-end workstation or set-top box, then the rendering task can be split across the two devices.In this paper, we explore one strategy for doing this.For each frame, the server generates a high-quality rendering and a low-quality rendering, subtracts the two, and sends the difference in compressed form.The client generates a matching low quality rendering, adds the decompressed difference image, and displays the composite.Within this paradigm, there is wide latitude to choose what constitutes a high-quality versus low-quality rendering.We have experimented with textured versus untextured surfaces, fine versus coarse tessellation of curved surfaces, Phong versus Gouraud interpolated shading, and antialiased versus nonantialiased edges.In all cases, our polygon-assisted compression looks subjectively better for a fixed network bandwidth than compressing and sending the high-quality rendering.We describe a software simulation that uses JPEG and MPEG-1 compression, and we show results for a variety of scenes.