image compression is increasingly employed in applications such as medical imaging, for reducing data storage requirement, and Internet video transmission, to effectively increase channel bandwidth. Similarly, militar...
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ISBN:
(纸本)0819454990
image compression is increasingly employed in applications such as medical imaging, for reducing data storage requirement, and Internet video transmission, to effectively increase channel bandwidth. Similarly, military applications such as automated target recognition (ATR) often employ compression to achieve storage and communication efficiencies, particularly to enhance the effective bandwidth of communication channels whose throughput suffers, for example, from overhead due to error correction/detection or encryption. In the majority of cases, lossy compression is employed due the resultant low bit rates (high compression ratio). However, lossy compression produces artifacts in decompressed imagery that can confound ATR processes applied to such imagery, thereby reducing the probability of detection (Pd) and possibly increasing the rate or number of false alarms (Rfa or Nfa). In this paper, the authors' previous research in performance measurement of compression transforms is extended to include (a) benchmarking algorithms and software tools, (b) a suite of error exemplars that are designed to elicit compression transform behavior in an operationally relevant context, and (c) a posteriori analysis of performance data. The following transforms are applied to a suite of 64 error exemplars: Visual Pattern imagecoding (VPIC [1]), Vector Quantization with a fast codebook search algorithm (VQ [2,3]), JPEG and a preliminary implementation of JPEG 2000 [4,5], and EBLAST [6-8]. compression ratios range from 2:1 to 200:1, and various noise levels and types are added to the error exemplars to produce a database of 7,680 synthetic test images. Several global and local (e.g., featural) distortion measures are applied to the decompressed test imagery to provide a basis for rate-distortion and rate-performance analysis as a function of noise and compression transform type.
Consideration of the geometry of spaces of textual images leads to description of ensembles of text classes via representation of such imagedata using a multi-scale multi-resolution method. A direct approach to stati...
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ISBN:
(纸本)0819445606
Consideration of the geometry of spaces of textual images leads to description of ensembles of text classes via representation of such imagedata using a multi-scale multi-resolution method. A direct approach to statistics of textual imagedata using 4 by 4 matrices of pixel values in the image of the document is introduced. The mathematical approach to analysis of occurrences of such pieces of a text image is Matrix Frequency Analysis (MFA). It is shown that MFA provides effective information on the classification of files using small sample sizes.
This Volume 4793 of the conference proceedings contains 34 papers. Topics discussed include mathematics of data/image coding, compression, and encryption and security, remote sensing and communication and compressive ...
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This Volume 4793 of the conference proceedings contains 34 papers. Topics discussed include mathematics of data/image coding, compression, and encryption and security, remote sensing and communication and compressive processing.
The suggested device includes a spatial light modulator (SLM) allowing varying the polarization state of an input illumination source. Attached to the SLM a sub wavelength grating is placed per each pixel of the devic...
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ISBN:
(纸本)0819445606
The suggested device includes a spatial light modulator (SLM) allowing varying the polarization state of an input illumination source. Attached to the SLM a sub wavelength grating is placed per each pixel of the device. This grating is used to encode the input information. The decoding is done by another sub wavelength grating. When the two gratings are attached a variation of the energetic efficiency between the two polarization states occurs. The polarization ratio encrypts the spatial information strewn. The sub wavelength grating are hard to copy and thus high encryption capability is obtained.
In this paper, a new encryption mode, which we call the 2D-encryption Mode, is presented. 2D-encryption Mode extends ID-encryption modes, as ECB, CBC and CTR, to two dimensions. It has good security and practical prop...
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In this paper, a new encryption mode, which we call the 2D-encryption Mode, is presented. 2D-encryption Mode extends ID-encryption modes, as ECB, CBC and CTR, to two dimensions. It has good security and practical properties. We first look at the type of problems it tries to solve, then describe the technique and its properties, and present a detailed mathematical analysis of its security, and finally discuss some practical issues related to its implementation.
In this work, we extend arithmetic coding and present a dataencryption scheme that achieves data compression and data security at the same time. This scheme is based on a chaotic dynamics, which makes use of the fact...
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ISBN:
(纸本)0819441899
In this work, we extend arithmetic coding and present a dataencryption scheme that achieves data compression and data security at the same time. This scheme is based on a chaotic dynamics, which makes use of the fact that the decoding process of arithmetic coding scheme can be considered as the repetition of Bernoulli shift map. dataencryption is achieved by controlling the piecewise linear maps by a secret key in three kinds of approach: (i) perturbation method, (ii) switching method, and (iii) source extension method. Experimental results show that the obtained arithmetic codes for a message are randomly distributed on the mapping domain [0,1) by using different keys without seriously deteriorating the compression ratio, and the transition of the orbits in the domain [0,1) is similar to the chaotic dynamics.
The first part of the article gives a brief examination of the state of art in terms of methodologies, hardware available and algorithms used in space applications. Particular emphasis is given to the lossless algorit...
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ISBN:
(纸本)0819441899
The first part of the article gives a brief examination of the state of art in terms of methodologies, hardware available and algorithms used in space applications. Particular emphasis is given to the lossless algorithms used and their characterization. In the second part a more detailed analysis, in terms of data entropy, is presented. At the end the preliminary results in the determination of compressibility of the file will be presented.
Earth observation missions have recently attracted a growing interest from the scientific and industrial communities, mainly due to the large number of possible applications capable to exploit remotely sensed data and...
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ISBN:
(纸本)0819441899
Earth observation missions have recently attracted a growing interest from the scientific and industrial communities, mainly due to the large number of possible applications capable to exploit remotely sensed data and images. Along with the increase of market potential, the need arises for the protection of the image products from non-authorized use. Such a need is a very crucial one even because the Internet and other public/private networks have become preferred means of data exchange. A crucial issue arising when dealing with digital image distribution is copyright protection. Such a problem has been largely addressed by resorting to watermarking technology. A question that obviously arises is whether the requirements imposed by remote sensing imagery are compatible with existing watermarking techniques. On the basis of these motivations, the contribution of this work is twofold: i) assessment of the requirements imposed by the characteristics of remotely sensed images on watermark-based copyright protection ii) analysis of the state-of-the-art, and performance evaluation of existing algorithms in terms of the requirements at the previous point.
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