We have developed an x-ray image scanning detector system named NExIS/sup TM/ with multi-energy capability that represents significant improvements over a previous version developed for automated baggage screening. Th...
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We have developed an x-ray image scanning detector system named NExIS/sup TM/ with multi-energy capability that represents significant improvements over a previous version developed for automated baggage screening. The system is built around a 1 mm pitch CZT pixel detector array and a new 32-channel signal processor chip called the xENA/sup TM/ IC The CZT array and xENA IC together enable x-ray detection at photon fluxes exceeding one million events per second per channel, at up to five energy levels with medium energy resolution. In the NExIS system, the detectors are abutted to form a seamless 128 mm long linear array on each detector module board. Up to sixteen boards can be tiled together to form scanning arms of various lengths. The board can also accommodate the use of 0.5 mm pixel pitch linear arrays. Multi-energy-bin images of compositionally and geometrically diverse objects have been acquired to demonstrate materials recognition via energy discrimination and image enhancement by suppression of scattered lower-energy radiation. applications of this multi-energy x-ray imaging system include security screening, medical imaging and industrial inspection.
We propose a construction of directional - or Gabor - continuous wavelets on the sphere. We provide a criterion to measure their angular selectivity. We finally discuss implementation issues and potential applications...
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ISBN:
(纸本)0819450804
We propose a construction of directional - or Gabor - continuous wavelets on the sphere. We provide a criterion to measure their angular selectivity. We finally discuss implementation issues and potential applications. The code for the spherical wavelet transform is avalaible in the YAWTB Matlab toolbox, http://***.
Wavelet transform is a powerful and useful mathematical tool for signalprocessing. In this paper detailed description of procedures for numerical integration and derivation in Haar domain has been done. These procedu...
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ISBN:
(纸本)0819450804
Wavelet transform is a powerful and useful mathematical tool for signalprocessing. In this paper detailed description of procedures for numerical integration and derivation in Haar domain has been done. These procedures are necessary both in control systems analysis, and, especially, for control design and development. A detailed comparison between classical methods of evaluation and the Haar way is presented and critically discussed.
Conventional techniques for signal analysis and processing in the time-frequency domain are not well adapted to digital processing of music signals. This restricts the features and quality of applications. We present ...
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ISBN:
(纸本)0819450804
Conventional techniques for signal analysis and processing in the time-frequency domain are not well adapted to digital processing of music signals. This restricts the features and quality of applications. We present the current status of a research initiative on this problem. A novel family of wavelet-like bases allows a tiling of the time-frequency plane that is better adapted to digital music signals. This will allow performance enhancements in all kinds of digital audio applications.
We present here an explicit time-domain representation of any compactly supported dyadic scaling function as a sum of harmonic splines. The leading term in the decomposition corresponds to the fractional splines, a re...
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ISBN:
(纸本)0819450804
We present here an explicit time-domain representation of any compactly supported dyadic scaling function as a sum of harmonic splines. The leading term in the decomposition corresponds to the fractional splines, a recent, continuous-order generalization of the polynomial splines.
The problem of image denoising has received more attention than the problem of image sharpening. In the paper, we propose that wavelet-based algorithms for image denoising can be used to perform image sharpening. Cons...
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ISBN:
(纸本)0819450804
The problem of image denoising has received more attention than the problem of image sharpening. In the paper, we propose that wavelet-based algorithms for image denoising can be used to perform image sharpening. Consequently, a variety of new image sharpening techniques becomes available. We examine the sharpening of natural images using an algorithm for image denoising with oriented complex 2D wavelets.
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