visual communication can be regarded as efficient only if the amount of information that it conveys from the scene to the observer approaches the maximum possible and the associated cost approaches the minimum possibl...
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ISBN:
(纸本)081941543X
visual communication can be regarded as efficient only if the amount of information that it conveys from the scene to the observer approaches the maximum possible and the associated cost approaches the minimum possible. To deal with this problem, Fales and Huck have integrated the critical limiting factors that constrain image gathering into classical concepts of communication theory. This paper uses this approach to assess the electro-optical design of the image gathering device. Design variables include the f-number and apodization of the objective lens, the aperture size and sampling geometry of the photodetection mechanism, and lateral inhibition and nonlinear radiance-to-signal conversion akin to the retinal processing in the human eye. It is an agreeable consequence of this approach that the image gathering device that is designed along the guidelines developed from communication theory behaves very much like the human eye. The performance approaches the maximum possible in terms of the information content of the acquired data, and thereby, the fidelity, sharpness and clarity with which fine detail can be restored, the efficiency with which the visual information can be transmitted in the form of decorrelated data, and the robustness of these two attributes to the temporal and spatial variations in scene illumination.
This paper describes the methodology of fractal coding and some new fractal compression results for gray scale images. image compression is discussed from a systems point of view. Current measures of compression perfo...
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ISBN:
(纸本)081941543X
This paper describes the methodology of fractal coding and some new fractal compression results for gray scale images. image compression is discussed from a systems point of view. Current measures of compression performance are not necessarily correlated with image system performance measures. For example, at a fixed `quality' level, bits/pixel type measures are correlated to transmission times for sending a single image under ideal conditions. However, such measures don't necessarily indicate interaction effects between image coding and systems issues such as communication channel errors and communication channel loading. It is proposed that a systems performance measure of image coding techniques be developed.
This paper describes an image modeling scheme based on wavelet signal decomposition and statistical texture analysis, and its application in model-based image coding. In this approach, the image being considered is fi...
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ISBN:
(纸本)081941638X
This paper describes an image modeling scheme based on wavelet signal decomposition and statistical texture analysis, and its application in model-based image coding. In this approach, the image being considered is first decomposed into octal signal bands which contains different spectral components of the images. Based on the property of the signal decomposition statistical texture analysis techniques are hierarchically employed to separate the image into different categories with distinct modeling parameters. Coding is performed based on the texture image model.
Biorthogonal wavelets or filterbanks are shown to be superior in coding gain performance than orthogonal ones for logarithmic subband decompositions (limited to iterative decomposition of the downsampled output of the...
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ISBN:
(纸本)081941638X
Biorthogonal wavelets or filterbanks are shown to be superior in coding gain performance than orthogonal ones for logarithmic subband decompositions (limited to iterative decomposition of the downsampled output of the analysis low-pass filter). As a consequence, for logarithmic decompositions, the optimal filter is not an ideal filter. This is shown for maximally regular biorthogonal and orthogonal filters, as well as filters designed to optimize the subband coding grain.
A lossy image compression technique, incorporating least squares cubic spline pyramids, vector quantization, predictive coding and arithmetic coding was developed for the compression and reconstruction of Magnetic Res...
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ISBN:
(纸本)081941638X
A lossy image compression technique, incorporating least squares cubic spline pyramids, vector quantization, predictive coding and arithmetic coding was developed for the compression and reconstruction of Magnetic Resonance images. Typical results of 29.76 dB Peak Signal-to-Noise ratio (PSNR) for 0.45 bits per pixel (bpp) compression, and 27.91 dB PSNR for 0.33 bpp, compare very favorably with other, recently reported, medical image compression results. Furthermore, block artifacts are absent from the recovered pictures.
A new scheme based on priori face knowledge and shift template method for fast face feature points extraction are presented in this paper. A fairly good accuracy and speed in detecting the feature points of eyebrows, ...
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ISBN:
(纸本)081941638X
A new scheme based on priori face knowledge and shift template method for fast face feature points extraction are presented in this paper. A fairly good accuracy and speed in detecting the feature points of eyebrows, eyes, nose and mouth have been achieved by a pair of complementary templates. It is shown by computer simulation that the scheme is very suitable for very low bit rate model-based image coding in real time applications.
In second generation image compression techniques the image to be compressed is first segmented. The pixels are divided into mutually exclusive spatial regions based on some criteria. After segmentation, the image con...
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This paper deals with the comparison in different motion vector coding methods suitable for motion compensated image communication systems. Both waveform and description coding techniques are presented and applied to ...
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ISBN:
(纸本)081941638X
This paper deals with the comparison in different motion vector coding methods suitable for motion compensated image communication systems. Both waveform and description coding techniques are presented and applied to a dense motion field. Only lossless compression is considered, and a reduction factor between 3:1 and 9:1 of the raw bit rate of the motion vectors can be reached. Although some of these techniques have already been used for the coding of motion information it would be greatly interesting to compare them in the same conditions, with intent to apply them to professional motion compensated applications as opposed to the particular case of motion compensated picture coding.
In this paper, we derive the optimal structuring elements of morphological filters in image restoration. The expected pattern transformation of random sets is presented. An estimation theory framework for random sets ...
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ISBN:
(纸本)081941638X
In this paper, we derive the optimal structuring elements of morphological filters in image restoration. The expected pattern transformation of random sets is presented. An estimation theory framework for random sets is subsequently proposed. This framework is based on the least mean difference (LMD) estimator. The LMD estimator is defined to minimize the cardinality of the expected pattern transformation of the set-difference of the parameter and the estimate. Several important results for the determination of the LMD estimator are derived. The LMD structuring elements of morphological filters in image restoration are finally derived.
This paper describes an object recognition technique based on the concept of local symmetry. A technique is described which can detect 1D features under situations of extreme low contrast. The effectiveness of the tec...
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ISBN:
(纸本)081941638X
This paper describes an object recognition technique based on the concept of local symmetry. A technique is described which can detect 1D features under situations of extreme low contrast. The effectiveness of the technique is shown through application to DNA autoradiographs. The technique is then expanded so that 2D objects can be located and then recognized. In the 2D case the resulting output of the technique is a locus which can be compared to those in a database. It is further shown how the technique is robust against changes in both scale and orientation.
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