This paper presents a modified QIM-JPEG2000 steganography which improves the previous JPEG2000 steganography using quantization index modulation (QIM). Since after-embedding changes on file size and PSNR by the modifi...
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This paper presents a modified QIM-JPEG2000 steganography which improves the previous JPEG2000 steganography using quantization index modulation (QIM). Since after-embedding changes on file size and PSNR by the modified QIM-JPEG2000 are smaller than those by the previous QIM-JPEG2000, the modified QIM-JPEG2000 should be more secure than the previous QIM-JPEG2000.
This paper proposes a clustering algorithm of depth pixels for consistency testing of multiview depth imagery. The testing addresses the inconsistencies among estimated depth maps of real world scenes by validating de...
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This paper proposes a clustering algorithm of depth pixels for consistency testing of multiview depth imagery. The testing addresses the inconsistencies among estimated depth maps of real world scenes by validating depth pixel connection evidence based on a hard connection threshold. With the proposed algorithm, we test the consistency among depth values generated from multiple depth observations using cluster adaptive connection thresholds. The connection threshold is based on statistical properties of depth pixels in a cluster or sub-cluster. This approach can improve the depth information of real world scenes at a given viewpoint. This allows us to enhance the quality of synthesized virtual views when compared to depth maps obtained by using fixed thresholding. Depth-image-based virtual view synthesis is widely used for upcoming multimedia services like three-dimensional television and free-viewpoint television.
Execution trace graph analysis of dataflow programs has been demonstrated to be an effective way for exploring and optimizing the design space of many core applications. In this work a novel transformation from the ex...
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Execution trace graph analysis of dataflow programs has been demonstrated to be an effective way for exploring and optimizing the design space of many core applications. In this work a novel transformation from the execution trace graph to an event driven linear system is proposed. It is also illustrated how the trace space of can be effectively reduced and well known system control techniques can be efficiently used in order to find close to optimal solutions. In particular, the problem of finding a bounded buffer size configuration is proposed and solved using a model predictive controller. Two design examples, a JPEG and an MPEG HEVC decoder have been used to demonstrate the effectiveness of the approach.
In this paper, a fully pipelined single chip is proposed for LOG-EXP still image compression. The design of the LOG-EXP image compression focuses on the high compression ratio of a complex texture (e.g. benchmark imag...
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ISBN:
(纸本)0780351231
In this paper, a fully pipelined single chip is proposed for LOG-EXP still image compression. The design of the LOG-EXP image compression focuses on the high compression ratio of a complex texture (e.g. benchmark image baboon) and high quality image, especially the PSNR requirement above 36. In comparison with the JPEG compression result (bpp=0.99, PSNR=26.9), this compression algorithm uses less bpp (bpp=0.87) to get a higher image quality (PSNR=36.38) for the benchmark image baboon. The entire LOG-EXP image compression system can be implemented on a single chip to yield a clock rate of 175 MHz which allow an input rate of 30 frames per second for 1024/spl times/1024 color images.
Identifying fragmented and deleted files from scattered digital storage become crucial needs in computer forensic. Storage media experience regular space fragmentation which gives direct consequence to the files syste...
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Identifying fragmented and deleted files from scattered digital storage become crucial needs in computer forensic. Storage media experience regular space fragmentation which gives direct consequence to the files system series. This paper specifies a case where the jpeg files are heavily fragmented with absent file header which contains maximum information for the stored data can be easily retrieved. The problem is formulated using statistical byte frequency analysis for identifying the group of jpeg file fragments. Several related works have addressed the issue of classifying variety types of file format with high occurrence of being fragmented such as avi, doc, wav file and etc. These files have been tagged as among the larger file format. We provide techniques for identifying the pattern of file fragments distribution and describe roles of selected clustering attributes. Finally, we provide experimental results presenting that the jpeg fragments distribution can be retrieved with quite small gap differences between the groups.
This paper introduces a public (OMNIQAD) database of omnidirectional (360°) images distorted by various ways and techniques, which can serve as a basic source for various research in the field of objective and su...
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This paper introduces a public (OMNIQAD) database of omnidirectional (360°) images distorted by various ways and techniques, which can serve as a basic source for various research in the field of objective and subjective quality assessment of an immersive multimedia content. Compressionbased distortions were applied using traditional JPEG and several emerging image compression standards, for instance, HEIC, AVIF and JPEG XL. Other types of distortion included Gaussian and impulse noise. The database offers eleven reference omnidirectional images of different character (374 distorted images in total). For the evaluation of distorted and compressionbased corrupted images, several objective quality metrics were adopted. Link to a repository containing the resulting objective scores and the database of images are included in this paper.
In this paper, the novel hardware sharing architectures are proposed for realizations of fast 4times4 and 8times8 forward/inverse integer transforms in the H.264/AVC. Based on matrix factorizations, the cost-effective...
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In this paper, the novel hardware sharing architectures are proposed for realizations of fast 4times4 and 8times8 forward/inverse integer transforms in the H.264/AVC. Based on matrix factorizations, the cost-effective architectures for fast one-dimensional (1D) 4times4 and 8times8 forward/inverse integer transforms can be derived through the Kronecker and direct sum operations. By applying the concept of hardware sharing, the proposed hardware schemes for fast integer transforms need less number of shifters and adders than the direct realization architecture, where the direct architecture just implements the individual 4times4 and individual 8times8 integer transforms independently. With low hardware cost and regular modularity, the proposed hardware sharing architectures are suitable for VLSI implementations to accomplish the H.264/AVC signal processing
The changes of statistical features can be used to detect the existence of secret messages in images. In this paper, it is indicated that statistical distribution of the whole AC coefficients, such as Generalized Gaus...
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The changes of statistical features can be used to detect the existence of secret messages in images. In this paper, it is indicated that statistical distribution of the whole AC coefficients, such as Generalized Gaussian, Laplacian, Cauchy, etc. can be greatly affected by JPEG quantization process. Furthermore, a constraint condition concerned with quantization step is presented under which the coefficients of individual channel can be fit Laplacian distribution. Based on the constraint condition above, a new steganalytic method, which can achieve a high degree of detection reliability, is also proposed.
Source camera identification is the process of discerning which camera has been used to capture a particular image. One approach to this problem is to identify the differences in standard processes among digital camer...
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Source camera identification is the process of discerning which camera has been used to capture a particular image. One approach to this problem is to identify the differences in standard processes among digital cameras. JPEG compression is one of the standard processes in most consumer-level cameras. It is a standard compression algorithm, however the size and quality tradeoff is at the manufacturers and the users' discretion. In this paper, we focus on identifying some features that can differentiate the characteristic quality and size tradeoff among different camera models. Simulation is carried out to evaluate the success rate of our method. The results show that our proposed features can provide useful information to classify images originating from a number of cameras
In this paper we describe the design and implementation of an efficient and compact image processing library for a digital still camera based on Siemens TriCore microcontroller-DSP processor. The library is designed f...
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In this paper we describe the design and implementation of an efficient and compact image processing library for a digital still camera based on Siemens TriCore microcontroller-DSP processor. The library is designed for use in both off-line (e.g. NT based Pentium platforms) as well as on-line (TriCore implementation). To satisfy the constraints of embedded systems the library was designed to operate on an input image using the concept of band processing. In such a method, the input image is divided into an appropriate number of data bands (strips). The image bands are then processed separately using a pipeline of band based operators. The processed bands are then collected into a single output image. Most of the operators incorporated in the library take advantage of the band processing mechanism and operate on a stream of such image bands. This scheme not only alleviates the memory space requirements but also lends itself to multithreading and parallel processing implementations with potential for even faster performance. The library was optimized in terms of code size (31 kilobytes) and processing speed (1.98 sec. on an 1008/spl times/800 input image in the acquisition mode of operation) to meet the current requirements of a size less than 250 kilobytes and a processing speed of less than 2 seconds/image.
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