Title :
Efficient image representation by anisotropic refinement in matching pursuit
Author :
Vandergheynst, Pierre ; Frossard, Pascal
Author_Institution :
Signal Process. Lab., Swiss Fed. Inst. of Technol., Lausanne, Switzerland
Abstract :
This paper presents a new image representation method based on anisotropic refinement. It has been shown that wavelets are not optimal to code 2-D objects which need true 2-D dictionaries for efficient approximation. We propose to use rotations and anisotropic scaling to build a real bi-dimensional dictionary. Matching pursuit then stands as a natural candidate to provide an image representation with an anisotropic refinement scheme. It basically decomposes the image as a series of basis functions weighted by their respective coefficients. Even if the basis functions can a priori take any form, bi-dimensional dictionaries are almost exclusively composed of two-dimensional Gabor functions. We present here a new dictionary design by introducing orientation and anisotropic refinement of a Gaussian generating function. The new dictionary permits to efficiently code 2-D objects and more particularly oriented contours. It is shown to clearly outperform common nonoriented Gabor dictionaries
Keywords :
image coding; image representation; transform coding; 2-D objects coding; Gaussian generating function; anisotropic refinement; anisotropic scaling; basis functions; bi-dimensional dictionary; image representation method; matching pursuit; orientation refinement; oriented contours; rotations; two-dimensional Gabor functions; Anisotropic magnetoresistance; Dictionaries; Discrete cosine transforms; Image coding; Image representation; Laboratories; Matching pursuit algorithms; Pursuit algorithms; Signal processing; Wavelet transforms;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 2001. Proceedings. (ICASSP '01). 2001 IEEE International Conference on
Conference_Location :
Salt Lake City, UT
Print_ISBN :
0-7803-7041-4
DOI :
10.1109/ICASSP.2001.941280