Geometrical grouplets

Grouplet orthogonal bases and tight frames are constructed with association fields that group points to take advantage of geometrical image regularities in space or time. These association fields have a multiscale geometry that can incorporate multiple junctions. A fast grouplet transform is computed with orthogonal multiscale hierarchical groupings. A grouplet transform applied to wavelet image coefficients defines an orthogonal basis or a tight frame of grouping bandlets. Applications to noise removal and image zooming are described. (C) 2008 Elsevier Inc. All rights reserved.