Penumbral images of neutron distributions from laser fusion experiments provided by large aperture imaging systems are degraded by signal-dependent noise. Most imageprocessing algorithms assume that the signal and th...
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ISBN:
(纸本)0819422355
Penumbral images of neutron distributions from laser fusion experiments provided by large aperture imaging systems are degraded by signal-dependent noise. Most imageprocessing algorithms assume that the signal and the noise are stationary. The purpose of this paper is to introduce a new approach using a locally adaptative non-stationary filter. This method modifies the stationary Wiener filter approach by trading off noise removal against resolution. We shall describe the method and show some results.
This paper describes a convergent algorithms that is able to construct a multi-scale fuzzy-wavelet system for efficient image recovery and compression. Given only part of the original image and a prescribed compressio...
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ISBN:
(纸本)0819422347
This paper describes a convergent algorithms that is able to construct a multi-scale fuzzy-wavelet system for efficient image recovery and compression. Given only part of the original image and a prescribed compression error bound, a fuzzy system is firstly constructed at the coarsest scale. The fuzzy rules and corresponding membership functions can be stably extracted, and linguistic knowledge can also be combined with numerical one to make the scheme more flexible. Residual based wavelet system is then built to refine the performance by reaching certain fine scales. To increase the compression ratio, a reduction technique is developed to delete redundant fuzzy rules and wavelet nodes to make the whole fuzz-wavelet system as small as possible. The resulting image representation of the given image from coarse to fine scale is suitable for progressive transmission and video indexing purposes. An illustrative example is used to demonstrate the effectiveness of the scheme.
The paper provides a closed form solution to least squares matching of the energy spectrum density of an orthonormal MRA-generating wavelet with that of a specified arbitrary signal. The authors had previously propose...
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ISBN:
(纸本)081942143X
The paper provides a closed form solution to least squares matching of the energy spectrum density of an orthonormal MRA-generating wavelet with that of a specified arbitrary signal. The authors had previously proposed algorithms for matching with samples of energy spectrum densities. An approach is also proposed to use matched wavelets in detecting an object in an image. Furthermore, the approach captures size, orientation and position information.
A novel wavelet packet image coder is introduced in this paper. It is based on our previous work on wavelet image coding using space-frequency. quantization (SFQ),(1) in which zerotree quantization and scalar quantiza...
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ISBN:
(纸本)0819422355
A novel wavelet packet image coder is introduced in this paper. It is based on our previous work on wavelet image coding using space-frequency. quantization (SFQ),(1) in which zerotree quantization and scalar quantization are jointly optimized in a rate-distortion sense. In this paper, we extend the powerful SFQ coding paradigm from the wavelet transform to the more general wavelet packet transformation.(2) The resulting wavelet packet coder offers a universal transform coding framework within the constraints of filter bank structures by allowing joint transform and quantizer design without assuming a priori statistics of the input image. In other words, the new coder adaptively chooses the representation to suit the image and the quantization to suit the representation. Experimental results show that, for some image classes, our new coder is capable of achieving the best coding performances among those in the published literature (e.g. for the standard 512 x 512 Barbara image coded at 0.5 b/p, our wavelet packet coder gets a 1.26 dB gain in PSNR over the SFQ coder(1) and 2.06 dB over Shaprio's embedded zerotree wavelet coder(3)).
Most digital signalprocessing methods have an underlying assumption of regularly-spaced data samples. However, many real-world data collection techniques generate data sets which are not sampled at evenly-spaced inte...
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ISBN:
(纸本)0819422134
Most digital signalprocessing methods have an underlying assumption of regularly-spaced data samples. However, many real-world data collection techniques generate data sets which are not sampled at evenly-spaced intervals, or which may have significant data dropout problems. Therefore, a method of interpolation is needed to model the signal on an even grid of arbitrary granularity. We propose the interpolation of nonuniformly sampled fields using a least- square fit of the data to a wavelet basis in a multiresolution setting.
In this paper, we propose a method of efficient computation of wavelet coefficients from DCT-based coded image/video signals. Block transform domain filtering is well suited for transcoding of such data. First direct ...
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ISBN:
(纸本)0819422134
In this paper, we propose a method of efficient computation of wavelet coefficients from DCT-based coded image/video signals. Block transform domain filtering is well suited for transcoding of such data. First direct transform domain processing removes the necessary of inverse transform. Second, the number of nonzero elements in the blocks are significantly smaller than spatial domain. Therefore, the amount of computation can be reduced accordingly. Finally, the block processing algorithm provides a parallel processing method. Hence a fast implementation of the algorithm is well suited.
Multiresolution representation of images provides a flexible tool for information rate control in video coding for transmission and storage purposes. In this work, the different spatial resolution capability of the hu...
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ISBN:
(纸本)0819422134
Multiresolution representation of images provides a flexible tool for information rate control in video coding for transmission and storage purposes. In this work, the different spatial resolution capability of the human visual system with the angular displacement from the foveal line of sight is exploited. When the region of interest of the observer can be determined with sufficient reliability, the resolution is regulated according to the expected receptive resolution. This leads to significant bitrate savings in some typical applications.
This paper presents a video coding scheme for very low bit rate applications. The coding approach relies on the notion of active meshes and can be viewed as a particular case of region-based coding. The active mesh is...
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ISBN:
(纸本)0780331923
This paper presents a video coding scheme for very low bit rate applications. The coding approach relies on the notion of active meshes and can be viewed as a particular case of region-based coding. The active mesh is used to efficiently represent and code the various regions of the scene as well as the motion information. The algorithm involves the following steps: Projection (time tracking of the regions), Partition and Motion coding, Synthesis, Modification of the mesh topology (introduction of new regions and elimination of useless regions) and texture coding.
Transform-based image coders exploit the information packing ability of some mathematical transforms in order to reduce the number of significant transform coefficients needed to accurately represent an image. Large c...
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ISBN:
(纸本)0819422134
Transform-based image coders exploit the information packing ability of some mathematical transforms in order to reduce the number of significant transform coefficients needed to accurately represent an image. Large coefficients are often associated with those regions where an image changes a lot, such as the boundaries between objects with differing visual characteristics. One way to reduce the number of significant transform coefficients is to segment an image into regions of similarity and then apply the transform to each region separately. We propose a novel image compression technique which first segments an image into arbitrary regions and then applies a region-adapted wavelet transform to each region.
Suppose that (sigma) is a sigmoidal function which is the activation function of a neural network. Under certain assumptions on the derivatives of σ, we show that a simple linear combination of dilates and translates...
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