this paper considers the use of data hiding strategies for improved color image compression. Specifically, color information is "piggybacked" on the luminance component of the image in order to reduce the ov...
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ISBN:
(纸本)0819444154
this paper considers the use of data hiding strategies for improved color image compression. Specifically, color information is "piggybacked" on the luminance component of the image in order to reduce the overall signal storage requirements. A practical wavelet-based data hiding scheme is proposed in which selected perceptually irrelevant luminance bands are replaced with perceptually salient chrominance components. Simulation results demonstrate the improvement in compression quality of the proposed scheme to SPIHT and JPEG at low bit rates. the novel technique also has the advantage that it can be used to further reduce the storage requirements of algorithms such as SPIHT which is optimized for grayscale image compression.
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.
this paper addresses the issue of robust data hiding in the presence of perceptual coding. Two common classes of data hiding schemes are considered: spread spectrum and quantization-based techniques. We identify analy...
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ISBN:
(纸本)0819441899
this paper addresses the issue of robust data hiding in the presence of perceptual coding. Two common classes of data hiding schemes are considered: spread spectrum and quantization-based techniques. We identify analytically the advantages of both approaches under the lossy compression class of "attacks." Based on our mathematical model, a novel hybrid data hiding algorithm which exploits the "best of both worlds" is presented. theoretical and simulation results demonstrate the superior robustness of the resulting hybrid scheme.
In this paper, a wavelet domain robust watermarking technique for still images is presented. Watermark message encoding is accomplished based on iterative error correction codes with reasonable decoder complexity, fol...
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ISBN:
(纸本)0819441899
In this paper, a wavelet domain robust watermarking technique for still images is presented. Watermark message encoding is accomplished based on iterative error correction codes with reasonable decoder complexity, followed by the codeword spreading over the whole image. Unlike the traditional technique, the proposed method utilizes the statistical property of a certain local area of an image in DWT domain for the watermark embedding and extraction. To minimize the perceptual degradation of the watermarked image, we propose an image compensation strategy (ICS) to make the watermark perceptually invisible, Experimental results demonstrate the robustness of the algorithm to many attacks, such as A/D and D/A processing, rescaling, and lossy compression.
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.
In this paper, comparative analysis on the characteristics of the Pseudo Random Sequence(PRS) and the Normal Random Sequence(NRS) which are used as a watermark for copyright protection and authentication about digital...
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ISBN:
(纸本)0819441899
In this paper, comparative analysis on the characteristics of the Pseudo Random Sequence(PRS) and the Normal Random Sequence(NRS) which are used as a watermark for copyright protection and authentication about digital media in the conventional digital watermarking systems. From the analysis, it is found that in case of the NRS, the detection of the watermark might be difficult from many crosscorrelation peak values resulted from other NRS codes because of the non-uniform distribution of 1 and 0 in those codes. However, for the case of the PRS, since it has the uniform distribution of the random number in the generated codes, there exists no crosscorrelation peaks. So the PRS is analyzed to have the robustness against possible attacks such as JPEG image compression and Gaussian noise compared withthe case of the NRS. therefore, in this paper, proving that PRS code become more robust watermark to attack by various image processing such as JPEG compression, Gaussian noise addition, etc by computer simulation.
In this work, a new watermarking scheme is proposed to authenticate an image. this scheme is capable to detect the alternation locations, if any. the basic idea of this scheme is to uniquely represent a given image by...
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ISBN:
(纸本)0819441899
In this work, a new watermarking scheme is proposed to authenticate an image. this scheme is capable to detect the alternation locations, if any. the basic idea of this scheme is to uniquely represent a given image by a short string-sequence. this string-sequence is based on a correlation coefficient statistic;where the relationship between two adjacent image-rows/columns is utilized. To generate this string-sequence a given image is divided into small blocks, where each block generates a different string-sequence. the Elliptic Curve Digital Signature Algorithm (ECDSA) is employed to sign these string-sequences to form an image dependant block-based watermark. Experimental results showed that the proposed watermark is highly sensitive to an alteration, and it can identify the location of any modified block in a given image.
Time-domain and frequency-domain spreading algorithms are presented in this paper. However, detection algorithm does not rely on correlation method, but based on patchwork method. Time-domain algorithm can survive tra...
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ISBN:
(纸本)0819441899
Time-domain and frequency-domain spreading algorithms are presented in this paper. However, detection algorithm does not rely on correlation method, but based on patchwork method. Time-domain algorithm can survive translation and clipping attacks. Frequency-domain algorithm is robust against compression attack. Embedding and detection functions are presented. Simulation results show the effectiveness of the algorithms.
Watermarking or steganography technology provides a possible solution in digital multimedia copyright protection and pirate tracking. Most of the current data hiding schemes are based oil spread spectrum modulation. A...
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ISBN:
(纸本)0819441899
Watermarking or steganography technology provides a possible solution in digital multimedia copyright protection and pirate tracking. Most of the current data hiding schemes are based oil spread spectrum modulation. A small value watermark signal is embedded into the content signal in some watermark domain. the information bits can be extracted via correlation. the schemes are applied both in escrow and oblivious cases. this paper reveals, through analysis and simulation, that in oblivious applications where the original signal is not available, the commonly used correlation detection is not optimal. Its maximum likelihood detection is analyzed and a feasible suboptimal detector is derived. Its performance is explored and compared withthe correlation detector. Subsequently a linear embedding scheme is proposed and studied. Experiments withimagedata hiding demonstrates its effectiveness in applications.
Scientific images collected by a remote platform are preferably transmitted to the ground station in lossless compressed form. However, the data rate to be transmitted has been rapidly increasing due to the developmen...
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ISBN:
(纸本)0819441899
Scientific images collected by a remote platform are preferably transmitted to the ground station in lossless compressed form. However, the data rate to be transmitted has been rapidly increasing due to the developments in sensor technology: the available downlink bandwidth has not increased accordingly. thus often imposing to resort to lossy compression. In particular, this paper deals withthe evaluation of the new JPEG2000 standard for the transmission of scientific images to the ground station. We focus on a particular type of system. namely the packet telemetry channel standardized by the CCSDS (,Consultative Committee for Space data Systems). which can be used for the transmission of both application data (e.g. images) and telecommand and control data. A performance evaluation is presented, in terms of error resilience and lossy compression performance. comparing the results achieved by JPEG2000 and the classical JPEG algorithm. the simulation of the transmission aspects, including the complete channel model, is performed by means of the TOPSIM IV simulator of communication systems.
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