Tight Frame Normal Map Compression

Abstract

We present a new powerful and flexible fixed-rate normal map compression algorithm with higher quality than existing schemes on a test suite of normal maps. Our algorithm encodes a tight box with uniform normals inside the box, and in addition, a special mode is introduced for handling slowly varying normals. We also discuss several error measures needed to understand the qualities of different algorithms. We believe the high quality of our technique makes it a potential candidate for inclusion in OpenGL ES.