EFFICIENT SPATIAL-DOMAIN IMPLEMENTATION OF A MULTISCALE IMAGE REPRESENTATION BASED ON GABOR FUNCTIONS

Gabor schemes of multiscale image representation are useful in many co mputer vision applications. However, the classic Gabor expansion is co mputationally expensive due to the lack of orthogonality of Gabor func tions. Some alternative schemes, based on the application of a bank of Gabor filters, have important advantages such as computational effici ency and robustness, at the cost of redundancy and lack of completenes s. in a previous work we proposed a quasicomplete Gabor transform, sui table for fast implementations in either space or frequency domains. R econstruction was achieved by simply adding together the even Gabor ch annels. We develop an optimized spatial-domain implementation, using o ne-dimensional 11-tap filter masks, that is faster and more flexible t han Fourier implementations. The reconstruction method is improved by applying fixed and independent weights to the Gabor channels before ad ding them together. Finally, we analyze and implement, in the spatial domain, two ways to incorporate a high-pass residual, which permits a visually complete representation of the image. (C) 1998 SPIE and IS&T. [S1017-9909(98)01601-8].