introduction: an efficient method of tomographic imaging in nuclear medicine is positron emission tomography (pet). compared to spect, pet has the advantages of higher levels of sensitivity, spatial resolution and more accurate quantification. however, high noise levels in the image limit its diagnostic utility. noise removal in nuclear medicine is traditionally based on fourier decomposition o...

there are two methods for identifying formation interface in oil wells: core analysis, which is a precise approach but costly and time consuming, and well logs analysis, which petrophysists perform, which is subjective and not completely reliable. in this paper, a novel coupled method was proposed to detect the formation interfaces using gr logs. second approximation level (a2) of gr log gained...

Digital signal processing and data analysis are very often used methods in a biomedical engineering research. In this work, the descriptions of two detection algorithms for ECG characteristic points are enclosed. The detection algorithms presented in this work are based on Pan and Tompkins’ algorithm and wavelet transform for signal de-noising and detection of QRS complexes. In the first approa...

Psychophysical representations built by Gabor visual chan-nels described in complex analytic form are shown to be related to thewavelet transform of visual stimuli under empirically plausible bandwidthconstraints. Analysis of the psychophysical wavelet representations ofone-dimensional stimuli eliciting some visual contrast illusions (Machbands and the Craik-Cornsweet-O’Brie...

The two-dimensional discrete cosine transform (DCT) can be found in the heart of many image compression algorithms. Specifically, the JPEG format uses a lossy form of compression based on that transform. Since the standardization of the JPEG, many other transforms become practical in lossy data compression. This article aims to analyze the use of these transforms as the DCT replacement in the J...

The clarity of medical image, which is directly acquired from the scanning machine, is very less. Image enhancement is one of the best and efficient techniques to increase the quality of image. A combined approach of different techniques such as Wavelet, Curvelet and Multiple Kernel Fuzzy C-Means algorithm was carry out in this paper. Wavelet and Curvelet transforms are used for denoising purpo...

Automatically understanding the content of a natural signal, like a sound or an image, is in general a difficult task. In their naive representation, signals are indeed complicated objects, belonging to high-dimensional spaces. With a different representation, they can however be easier to interpret. This thesis considers a representation commonly used in these cases, in particular for the anal...

This paper proposes the use of a modified Morlet wavelet in order to demodulate fringe patterns in conjunction with the one-dimensional continuous wavelet transform (1D-CWT). Our investigations demonstrate that the modified Morlet wavelet produces better results compared to the conventional Morlet wavelet when used in fringe pattern analysis. This novel technique offers superior performance in ...