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A fast algorithm is developed for the directional correlation of scalar band-limited signals and band-limited steerable filters on the sphere. The asymptotic complexity associated to it through simple quadrature is of order O(L^5), where 2L stands for the ...
We explore a new approach for synthesizing moiré images that can be used for authentication of documents. For synthesizing moiré images, we need two layers: a base layer made of replicated bands or parallelograms and a revealing layer made of transparent l ...
This dissertation investigates wavelets as a multiscale tool on non-Euclidean manifolds. The growing importance of using non-Euclidean manifolds as a geometric model for data comes from the diversity of the data collected. In this work we mostly deal with ...
The standard separable two-dimensional (2-D) wavelet transform (WT) has recently achieved a great success in image processing because it provides a sparse representation of smooth images. However, it fails to capture efficiently one-dimensional (1-D) disco ...
An encoder/decoder system for 3D volumetric medical data is proposed. The system allows fast access to any 2D image by decoding only the relevant information from each subband image and thus provides minimum decoding time. This will be of immense use for t ...
We describe a spatially adaptive algorithm for image interpolation. The algorithm uses a wavelet transform to extract information about sharp variations in the low-resolution image and then implicitly applies interpolation which adapts to the image local s ...
The paper illustrates a procedure based on the continuous-wavelet transform (CWT) for the analysis of voltage transients due to line faults, and discusses its application to fault location in power distribution systems. The analysis carried out shows that ...
In this paper we exploit the Continuous Wavelet Transform (CWT) on the two dimensional sphere, introduced previously by two of us, to build associated Discrete Wavelet Frames. We first explore half-continuous frames, i.e., frames where the position remains ...
This paper discusses an improved pyramid for spatially scalable video coding. We introduce additional update steps in the analysis and the synthesis of the Laplacian pyramid. Our pyramid is able to control efficiently the quantization noise energy in the r ...
We propose a method to encode a 3D magnetic resonance image data and a decoder in such way that fast access to any 2D image is possible by decoding only the corresponding information from each subband image and thus provides minimum decoding time. This wil ...