Two papers from the VIS Group Stuttgart describe implementations of wavelet-based multi-resolution analysis using OpenGL. Wavelets are commonly used for signal processing and image compression (e.g. for JPEG 2000). The papers focus on details of implementing wavelet decomposition and reconstruction using graphics hardware, and develop a scaled version of wavelet analysis that constrains data to the [0,1] range of fixed-point frame buffers. See also the project page for more about hardware-based filtering. (Hardware-Based Wavelet Transformations. Matthias Hopf and Thomas Ertl. Workshop on Vision, Modeling, and Visualization 1999, pp 317-328. Hardware-Accelerated Wavelet Transformations. Matthias Hopf and Thomas Ertl. Proc. EG/IEEE TCVG Symposium on Visualization VisSym 2000, pp 93-103.)