This paper presents a simple method to segment JPEG2000 images based on the features extracted from the MQ table such that the burden of decompressing computations can be avoided. The feature vectors are segmented by ...
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This paper presents a simple method to segment JPEG2000 images based on the features extracted from the MQ table such that the burden of decompressing computations can be avoided. The feature vectors are segmented by using the modified CTM algorithm. In which, a rate-distortion based scheme is proposed to determine the parameter ε of CTM in an adaptive manner. Experimental results show that the modified CTM algorithm with the MQ table based features is suitable for JPEG2000 image segmentation. In addition, the segmentation results even at low-middle bpp rates are satisfactory, which is advantageous to the communication applications.
Digital watermarking is a topic that has recently gained increasing attention all over the world, we divide singular values of watermark image into two parts, then embed them into the LL and HH subband of DWT domain o...
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Digital watermarking is a topic that has recently gained increasing attention all over the world, we divide singular values of watermark image into two parts, then embed them into the LL and HH subband of DWT domain of the original image. Emulational experiments are done in Matlab, Experimental results demonstrate that the watermark is invisible and robust against kinds of classical attacks.
The statistical footprint left by JPEG compression can be a valuable source of information for the forensic analyst. Recently, it has been shown that a suitable anti-forensic method can be used to destroy these traces...
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The statistical footprint left by JPEG compression can be a valuable source of information for the forensic analyst. Recently, it has been shown that a suitable anti-forensic method can be used to destroy these traces, by properly adding a noise-like signal to the quantized DCT coefficients. In this paper we analyze the cost of this technique in terms of introduced distortion and loss of image quality. We characterize the dependency of the distortion on the image statistics in the DCT domain and on the quantization step used in JPEG compression. We also evaluate the loss of quality as measured by means of a perceptual metric, showing that a perceptually-optimized version of the anti-forensic method fails to completely conceal the forgery. Our conclusion is that removing the traces of the JPEG compression history could be much more challenging than it might appear, as anti-forensic methods are bound to leave characteristic traces.
Face recognition in JPEG compressed domain is one of the recent challenges in biometric systems, leading to a considerable reduction in computational overhead caused by decompression process, without any notable degra...
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Face recognition in JPEG compressed domain is one of the recent challenges in biometric systems, leading to a considerable reduction in computational overhead caused by decompression process, without any notable degradation in the recognition rates. In this paper, the potential of using a limited number of lowest frequency coefficients in JPEG compressed domain face recognition is investigated, to obtain a considerable reduction in computational complexity, as well as improving the recognition rates. The proposed method preselects lowest frequency coefficients including all of the DC coefficient and a limited number of the AC coefficients for face recognition process. Simulations have been done on four of the FERET databases using different number of preselected coefficients. Experimental results show that the proposed method outperforms existing methods in recognition rate, as well as in computational and space complexity aspects.
The TVA metadata allows consumers to find, navigate, and manage contents through a variety of terminal devices including PDR, DTV, and IPTV. In general, a TVA metadata description is delivered from a content provider ...
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The TVA metadata allows consumers to find, navigate, and manage contents through a variety of terminal devices including PDR, DTV, and IPTV. In general, a TVA metadata description is delivered from a content provider to a terminal device over a transport link. Because such metadata description can become very large, it is essential to encode each fragment of the metadata description in a compressed format before the delivery and then decode the encoded fragments at the terminal device. This paper proposes a new encoding procedure for TVA metadata based on the EXI and presents performance comparison results between the proposed encoding procedure and the existing TVA encoding procedure.
In recent years, the use of extensible processors has been increased. Extensible processors extend the base instruction set of a general-purpose processor with a set of custom instructions. Custom instructions that ca...
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In recent years, the use of extensible processors has been increased. Extensible processors extend the base instruction set of a general-purpose processor with a set of custom instructions. Custom instructions that can be implemented in special hardware units make it possible to improve performance and decrease power consumption in extensible processors. The key issue involved is to generate and select automatically custom instructions from a high-level application code. In this paper, we propose an efficient and flexible algorithm for the exact enumeration of custom instructions. The algorithm can be tuned to generate all possible patterns or only connected patterns. Compared to a previously proposed well-known algorithm, our algorithm can achieve orders of magnitude speedup.
Copy-move is a common manipulation of digital image tampering. Block matching after feature extraction is mostly applied method to detect this kind of forgery. In this paper, we propose an efficient copy-move detectin...
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Copy-move is a common manipulation of digital image tampering. Block matching after feature extraction is mostly applied method to detect this kind of forgery. In this paper, we propose an efficient copy-move detecting scheme with the capacity of some post-processing resistances. The image is divided into fixed-size overlapped blocks, and then non-negative matrix factorization (NMF) coefficients are extracted from list of all blocks. It is worth noting that all the coefficients are quantized before matching, in other words, we could use relatively few data to interpret a sub-image. Besides, we apply lexicographical sorting method to reduce the probability of invalid matching. Lastly we measure the hamming distance of each block pair in the matching procedure, if the distance is shorter than a threshold, we localize them as the tampering areas. Experimental results show the efficacy of our scheme.
In this paper, we propose a format compliant feedback encryption scheme for JPEG2000 by using a chaotic pseudo-random bit generator. This chaotic pseudo-random bit generator is purturbed to enhance cryptographic prope...
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In this paper, we propose a format compliant feedback encryption scheme for JPEG2000 by using a chaotic pseudo-random bit generator. This chaotic pseudo-random bit generator is purturbed to enhance cryptographic properties such as cycle length and statistical properties so that it can be used to construct our stream ciphers with higher security. The encrypting time by using our proposed scheme is calculated and compared with other scheme. In order to demonstrate the key sensitivity, we test the performance of our proposed scheme with one of the parameters being slightly changed.
Immense increase in the number of multimedia content accessible from television and internet with the help developing technologies reveals efficient supervision and classification of such content as a problem. Relevan...
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Immense increase in the number of multimedia content accessible from television and internet with the help developing technologies reveals efficient supervision and classification of such content as a problem. Relevance feedback is a technique which relies on evaluation of retrieval results by humans and enables reduce the semantic gap between ideas and low level representations. Content based high level classification system may employ relevance feedback for improved retrieval performance. In this paper, different relevance feedback algorithms, which can be utilized to increase generalized semantic classification performance, are discussed and compared inside an experimental framework. Some improvements are also proposed over obtained results.
JPEG coding leaves characteristic footprints that can be leveraged to reveal doctored images, e.g. providing the evidence for local tampering, copy-move forgery, etc. Recently, it has been shown that a knowledgeable a...
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JPEG coding leaves characteristic footprints that can be leveraged to reveal doctored images, e.g. providing the evidence for local tampering, copy-move forgery, etc. Recently, it has been shown that a knowledgeable attacker might attempt to remove such footprints by adding a suitable anti-forensic dithering signal to the image in the DCT domain. Such noise-like signal restores the distribution of the DCT coefficients of the original picture, at the cost of affecting image quality. In this paper we show that it is possible to detect this kind of attack by measuring the noisiness of images obtained by re-compressing the forged image at different quality factors. When tested on a large set of images, our method was able to correctly detect forged images in 97% of the cases. In addition, the original quality factor could be accurately estimated.
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