This paper focuses on two problems, authentication and copyrights protection, faced by digital media in general and digital images in particular. We discuss how two algorithms defined separately can be combined to pro...
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This paper focuses on two problems, authentication and copyrights protection, faced by digital media in general and digital images in particular. We discuss how two algorithms defined separately can be combined to produce a secure digital camera which provides a solution to these problems. First, a robust quantization based wavelet domain scheme is applied to embed a robust watermark in the image for the purpose of owner identification. After that, a semi-fragile scheme is used to watermark the robust watermarked image for authentication. Experimental results show that recovered robust watermark had high correlation with the embedded robust watermark after different attacks. Under perfect conditions, recovered fragile watermark also showed perfect correlation with embedded fragile watermark, but after attacks, the similarity index dropped indicating that image is not authentic.
This paper presents a novel semi-fragile watermarking scheme for image authentication and tamper detection. The proposed scheme extracts content-based image features from the approximation subband in the wavelet domai...
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This paper presents a novel semi-fragile watermarking scheme for image authentication and tamper detection. The proposed scheme extracts content-based image features from the approximation subband in the wavelet domain to generate two complementary watermarks. Specifically, we generate an edge-based watermark sequence to detect any changes after manipulations. This edge-based watermark encodes the invariant relationship between quantized wavelet coefficients after incidental distortions. We also generate the content-based watermark to localize tampered regions. Both watermarks are embedded into the high frequency wavelet domain to ensure the watermark invisibility. Our extensive experimental results show that the proposed scheme outperforms the peer scheme and can successfully identify intentional tampering and incidental modification, and localize maliciously tampered regions.
This paper presents the design of the area optimized integer two dimensional discrete cosine transform (2-D DCT) used in H.264/AVC codecs. The 2-D DCT calculation is performed by utilizing the separability property, i...
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This paper presents the design of the area optimized integer two dimensional discrete cosine transform (2-D DCT) used in H.264/AVC codecs. The 2-D DCT calculation is performed by utilizing the separability property, in such a way that 2-D DCT is divided into two 1-D DCT calculation that are joined through a common memory. Due to its area optimized approach, the design will find application in mobile devices. Verilog hardware description language (HDL) in cadence environment has been used for design, compilation, simulation and synthesis of transform block in 0.18 mu TSMC technology.
In this work, a fast mode decision algorithm for H.264/AVC is proposed. H.264/AVC achieves high coding efficiency by introducing rate-distortion optimized (RDO) method. However, it induced very high computation comple...
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In this work, a fast mode decision algorithm for H.264/AVC is proposed. H.264/AVC achieves high coding efficiency by introducing rate-distortion optimized (RDO) method. However, it induced very high computation complexity. In order to reduce the computation complexity of the encoder of H.264/AVC, the proposed algorithm efficiently reduces the candidate modes. The proposed algorithm includes an early skip mode decision method and an adaptive rate distortion cost threshold for early INTER mode decision. An complexity reduction algorithm for INTRA modes which uses the information during INTER mode selection is also proposed. The experimental results show that compared with full-search algorithm the proposed algorithm can achieve up to 70-89% speed up with very slight PSNR loss.
Leakage power becomes a key challenge and occupies an increasing portion of the total power consumption in nano-scale circuit design. There are many novel cache designs to reduce the leakage power based on the charact...
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Leakage power becomes a key challenge and occupies an increasing portion of the total power consumption in nano-scale circuit design. There are many novel cache designs to reduce the leakage power based on the characteristics of programs. One of them is Asymmetric SRAM that can reduce leakage power on cache while storing bit "0". In this paper, we propose two algorithms, value-position-switch algorithm and code-bit-switch algorithm, to make the JPEG image bias on bit "0" based on Asymmetric SRAM. The value-position-switch algorithm and codebit-switch algorithm can reduce the amount of bit "1" in Huffman coded data up to 7.33% and 25.20%, respectively. The overheads of instruction count, cycle count and power consumption for these two algorithms are negligible (< 0.3%). To the best of our knowledge, this paper is the first study to reduce leakage power in application-level by utilizing the feature of Asymmetric SRAM.
Two essential benefits, the resistance to the counterfeiting attack and the tamper localization accuracy, of the fragile watermarking methods are mutually restricted. In this paper, a novel distributed block-dependent...
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Two essential benefits, the resistance to the counterfeiting attack and the tamper localization accuracy, of the fragile watermarking methods are mutually restricted. In this paper, a novel distributed block-dependent watermarking method is proposed to gain both benefits by inserting the block watermark into other chosen blocks. Further, the proposed method can be easily implemented in the DWT domain for authenticating JPEG2000 images. Experimental results show that the method can resist the counterfeiting attack effectively as other block-dependent watermarking methods, while sustain the high localization accuracy as the block-independent watermarking method. It is also demonstrated that the proposed method can successfully authenticate the JPEG2000 images while recognize the malicious tampers, such as crop-and-replacement, deletion, and so on.
In this paper, we study the affect of using the spiral architecture instead of the square block decomposition and in fractal compression. Comparisons with other systems like the conventional square and the simplified ...
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ISBN:
(纸本)9781424458424
In this paper, we study the affect of using the spiral architecture instead of the square block decomposition and in fractal compression. Comparisons with other systems like the conventional square and the simplified fractal compression systems are presented. A comparison with standard JPEG system is also introduced. We applied these types of fractal compression on a video sequence. We found that in the case of using the spiral architecture in fractal compression, the produced or decoded image or video has a better visual quality than that produced with the conventional square system and the previously proposed simplified system. We found also that all types of fractal compression are better than the JPEG standard.
In this paper, a fast mode decision algorithm for P-Slices in H.264/AVC is proposed. The algorithm is based on probabilistic learning. Spatial correlation between neighboring macroblocks is exploited by a Bayesian cla...
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In this paper, a fast mode decision algorithm for P-Slices in H.264/AVC is proposed. The algorithm is based on probabilistic learning. Spatial correlation between neighboring macroblocks is exploited by a Bayesian classifier to predict the best candidate mode for the current macroblock. Early termination strategy is also designed for skipping unnecessary mode checking. Extensive experiments show that the proposed algorithm can achieve 60%-70% encoding time reduction compared to JM10.0, and only yields a negligible PSNR loss and little increment in total bits and bit rates.
This paper proposes an application oriented four layered quality of service (QoS) stack for wireless sensor networks (WSN), including a supporting system architecture for interacting with WSNs using the MPEG-21 multim...
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This paper proposes an application oriented four layered quality of service (QoS) stack for wireless sensor networks (WSN), including a supporting system architecture for interacting with WSNs using the MPEG-21 multimedia framework in an medical application setting. The application of the WSNs is signal processing algorithms reporting elaborated observed sensor data to external users. The QoS model supports the tradeoff between end-users expected QoS combined with optimized energy consumption. The MPEG-21 standard is chosen as the media resource framework due to the fact that future hospitals will have networks comprising WSNs supporting an always increasing amount of both low rate medical sensor data as well as high rate audiovisual content. Furthermore due to the heterogeneous set of user terminals and network resources, media adaptation will become important to provide reliable and robust quality of service. In this paper, we argue for an extension of the MPEG-21 terminology for use in biomedical wireless sensor networks and incorporate the requirements needed for medical applications.
Measurement of image and video quality is crucial for many image-processing algorithms, such as acquisition, compression, restoration, enhancement and reproduction. In this paper a no-reference quality assessment algo...
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Measurement of image and video quality is crucial for many image-processing algorithms, such as acquisition, compression, restoration, enhancement and reproduction. In this paper a no-reference quality assessment algorithm for JPEG2000 images is analyzed. This algorithm uses the changes in image statistical model due to wavelet coefficient quantization. We calculate suboptimal parameters of the algorithm and provide comparison between no-reference algorithm and two full-reference methods: peak signal to noise ratio (PSNR) and structural similarity index (SSIM). Examples of images quality assessment are provided.
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