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VLSI architecture for quadtree-based fractal image coding

IEE PROCEEDINGS-COMPUTERS AND DIGITAL TECHNIQUES 2001年第4-5期148卷 141-146页

作者： Lee, S Omachi, S Aso, H Tohoku Univ Grad Sch Engn Dept Elect & Commun Engn Aoba Ku Sendai Miyagi 9808579 Japan

A VLSI architecture for flexible-size fractal image coding is proposed. The main features of this architecture are that it is capable of performing fractal image coding based on quadtree partitioning without the external memory for the fixed domain pool and uses only local data communication. Since large domain blocks consist of small domain blocks, the calculations of distortion for all kinds of domain block are performed using only the domain pool, which is extracted from the smallest range blocks of the neighbouring processors. This architecture has a fast comparison module which can compute the distortions between a range block and the eight isometric transformations of domain blocks by one full rotation around the centre.

关键词： Pattern recognition and computer vision equipment smallest range blocks fractals Combinatorial mathematics fast comparison module VLSI architecture VLSI isometric transformations File organisation local data communication flexible-size fractal image coding Graphics techniques Semiconductor integrated circuits Computer vision and image processing techniques large domain blocks image coding quadtrees quadtree partitioning Signal processing and conditioning equipment and techniques distortion image processing equipment image and video coding neighbouring processors small domain blocks quadtree based fractal image coding Signal processing theory

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Multimedia streaming using partially reliable concurrent multipath transfer for multihomed networks

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IET COMMUNICATIONS 2011年第5期5卷 587-597页

作者： Huang, C. -M. Lin, M. -S. Natl Cheng Kung Univ Dept Comp Sci & Informat Engn Lab Multimedia Mobile Networking Tainan 70101 Taiwan

The authors propose a partially reliable-concurrent multipath transfer (PR-CMT) protocol for multimedia streaming. The novelty of PR-CMT is to combine techniques of CMT's concurrent multipath transfer, PR-SCTP's partially reliable transmission and prioritised stream transmission. Moving picture experts group (MPEG) frames are with varying priorities and lifetime. PR-CMT can transmit important frames before other frames but does not transmit lifetime expired frames. The combination of the aforementioned techniques, however, causes imprecise congestion window and receiver buffer blocking problems without suitable control. Consequently, the throughput and video quality degrade. PR-CMT adopts the concept of delay abandoning data to resolve the imprecise cwnd and the receiver buffer blocking problems. The simulation results show that PR-CMT can precisely infer cwnd. Most importantly, PR-CMT can prevent large gaps between two playable frames to have good video quality.

关键词： image and video coding video quality multimedia communication Multimedia communications Protocols video coding receiver buffer blocking problems MPEG frames multimedia streaming partially reliable concurrent multipath transfer protocol protocols imprecise congestion window multihomed networks

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Optimal look-up table-based data hiding

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IET SIGNAL PROCESSING 2011年第2期5卷 171-179页

作者： Wang, X. Zhang, X. -P. Ryerson Univ Dept Elect & Comp Engn Toronto ON M5B 2K3 Canada

In this study, the authors present a novel data hiding scheme using the minimum distortion look-up table (LUT) embedding that achieves good distortion-robustness performance. LUT-based data hiding is a simple and efficient way to embed information into multimedia content for various applications, such as transaction tracking and database annotation. The authors find it possible to optimally reduce the data hiding-introduced distortion by designing the LUT according to the distribution of the host at a given robustness level. The authors first analyse the distortion introduced by LUT embedding and formulate its relationship with run constraints of LUT to construct an optimal coding problem. Subsequently, a Viterbi algorithm is presented to find the minimum distortion LUT. Then a new practical data hiding scheme using the optimal LUT is applied in the wavelet domain. Theoretical analysis and numerical results show that the new LUT design achieves not only less distortion but also more robustness than the traditional LUT-based data embedding schemes under common attacks such as Gaussian noise and JPEG compression.

关键词： Computer vision and image processing techniques data compression image and video coding wavelet transforms telecommunication security table lookup Codes image coding distortion Viterbi coding Viterbi decoding JPEG compression LUT-based data hiding database annotation wavelet domain look-up table Integral transforms Data handling techniques transaction tracking

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Secure private fragile watermarking scheme with improved tampering localisation accuracy

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IET INFORMATION SECURITY 2010年第3期4卷 137-148页

作者： Bravo-Solorio, S. Gan, L. Nandi, A. K. Aburdene, M. F. Univ Liverpool Dept Elect Engn & Elect Liverpool L69 3GZ Merseyside England

In some applications, such as surveillance cameras, it is essential that images acquired with the same device be deemed distinct. To fulfil this requirement, many fragile watermarking methods need to employ a different key for every single image. Keeping track of the correct key associated with each image may become a challenging task as the number of images increases. An existing image index-based scheme as a suitable solution for this problem is revisited, and its security limitations in applications are highlighted where higher localisation accuracy is required. Then, a new fragile watermarking scheme that enhances the localisation accuracy is proposed, while hindering brute force attacks. Experiments demonstrate that the proposed scheme outperforms the state-of-the-art private fragile watermarking methods.

关键词： private fragile watermarking scheme data privacy Computer vision and image processing techniques image and video coding image coding brute force attacks watermarking Data security image index-based scheme tampering localisation accuracy

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Efficient block prediction-based coding of computer screen images with precise block classification

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IET image PROCESSING 2011年第4期5卷 306-314页

作者： Juliet, S. Ebenezer Florinabel, D. Jemi Dr Sivanthi Aditanar Engn Coll IT Dept Tiruchendur 628215 India Dr Sivanthi Aditanar Engn Coll Dept Comp Sci & Engn Tiruchendur 628215 India

This study presents a precise, one-pass block classification algorithm for efficient coding of computer screen images like power-point presentations, webpages and wall papers. The objective is to minimise the loss of visual quality of text during compression by separating text information which needs high spatial resolution than the pictures and background. It segments computer screen images into text/graphic, picture/background blocks by computing the statistical feature based on discrete wavelet transforms coefficients in the detail sub-bands of each 8 x 8 block, and then compresses the text/graphics pixels losslessly with a two-mode block prediction coding and the background pixels with the lossy JPEG algorithm. The proposed scheme performs accurate block classification of text information with different fonts, sizes and ways of arrangement from the background image, so that text/graphics blocks are compressed at higher quality than background image blocks. Experimental results show that the proposed method minimises block classification error and improves the value of peak signal-to-noise ratio significantly than standard JPEG, JPEG-2000 and H. 264/AVC-I, while keeping competitive compression ratio and visually lossless quality of text information.

关键词： block codes visual quality signal to noise ratio lossy JPEG algorithm discrete wavelet transforms Computer vision and image processing techniques block prediction coding image and video coding spatial resolution image coding Integral transforms text information discrete wavelet transform coefficient block classification algorithm block classification error statistical feature computer screen images

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Geometric correction code-based robust image watermarking

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IET image PROCESSING 2023年第13期17卷 3660-3669页

作者： Zhou, Zhili Zhu, Jianyu Su, Yuecheng Wang, Meimin Sun, Xingming Nanjing Univ Informat Sci & Technol Jiangsu Engn Ctr Network Monitoring Nanjing Peoples R China Nanjing Univ Informat Sci & Technol Sch Comp & Software Nanjing Peoples R China

Digital image watermarking is one of the effective schemes to protect the copyrights of still images. However, the existing watermarking schemes are still not robust enough to the common geometric transformation attacks such as arbitrary rotation, scaling and shifting with desirable hiding capacity. To address this issue, we propose a robust watermarking scheme based on geometric correction codes (GCCs). In this scheme, the watermark and pre-set GCCs are combined and embedded into a cover image to obtain the watermarked image. At the stage of watermark extraction, the watermarked image, under a variety of geometric transformation attacks, can be geometrically corrected by minimising the difference between the extracted and the original GCCs, then the watermark is extracted from the watermarked image. The experiments demonstrate that, compared to the typical watermarking schemes, the proposed scheme achieves much higher robustness to the common geometric transformation attacks and comparable invisibility with the same embedding capacity.

关键词： image watermarking Computer vision and image processing techniques watermarking image coding copyright image and video coding robust watermarking scheme cover image existing watermarking schemes Data security Integral transforms geometric correction code-based robust image watermarking effective schemes data encapsulation typical watermarking schemes watermarked image watermark extraction common geometric transformation attacks digital image watermarking geometric correction codes

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Resource management to increase connection capacity of real-time streaming in mobile WiMAX

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IET COMMUNICATIONS 2010年第9期4卷 1108-1115页

作者： Tsai, M. -H. Sung, J. -T. Huang, Y. -M. Natl Cheng Kung Univ Dept Engn Sci Tainan 70101 Taiwan

With large network coverage, high transmission rate, strong quality of service (QoS) assurance and inexpensive deployment cost, mobile WiMAX has emerged as one of the most promising broadband wireless access technologies. However, resource management is still a challenging issue between system capacity and user gratification, especially for multimedia transmission which ordinarily requires strict delay constraints. In this study, the authors propose an adaptive call admission control in order to efficiently increase system capacity. The control mechanism can admit an incoming video on demand (VOD) connection establishing even without sufficient idle slots/bandwidth to meet the QoS requirement. With consideration of the existing VOD user stream buffer (USB), our scheduling mechanism performs adaptive admission control and QoS provision feasible each time. Also employing adaptive modulation and coding (AMC) scheme, each connection keep its fluency of real-time video performance over dynamic wireless channel status. The authors evaluate the concurrent stream connection number and connection blocking probability with different resource management strategies.

关键词： image and video coding connection capacity real-time streaming adaptive call admission control video on demand mobile WiMAX multimedia transmission video streaming quality of service broadband networks Mobile radio systems video coding mobility management (mobile radio) WiMax Network management high transmission rate resource management broadband wireless access technologies adaptive modulation and coding QoS assurance

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Improving histogram-based reversible data hiding by interleaving predictions

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IET image PROCESSING 2010年第4期4卷 223-234页

作者： Yang, C-H. Tsai, M-H. Natl Pingtung Univ Educ Dept Comp Sci Pingtung 900 Taiwan Natl Sun Yat Sen Univ Dept Comp Sci & Engn Kaohsiung 80424 Taiwan

Data hiding is an important way of realising copyright protection for multimedia. In this study, a new predictive method is proposed to enhance the histogram-based reversible data hiding approach on grey images. In those developed histogram-based reversible data hiding approaches, their drawbacks are the number of predictive values less to the number of pixels in an image. In these interleaving prediction methods, the predictive values are as many as the pixel values. All predictive error values are transformed into histogram to create higher peak values and to improve the embedding capacity. Moreover, for each pixel, its difference value between the original image and the stego-image remains within +/- 1. This guarantees that the peak signal-to-noise ratio (PSNR) of the stego-image is above 48 dB. Experimental results show that the histogram-based reversible data hiding approach can raise a larger capacity and still remain a good image quality, compared to other histogram-based approaches.

关键词： grey images Computer vision and image processing techniques data encapsulation image and video coding multimedia image coding Data security PSNR histogram-based reversible data hiding copyright protection image colour analysis interleaving prediction method stego-image peak signal-to-noise ratio predictive error value

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H.264 video watermarking with secret image sharing

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IET image PROCESSING 2011年第4期5卷 349-355页

作者： Chen, W. -M. Lai, C. -J. Wang, H. -C. Chao, H. -C. Lo, C. -H. Natl Ilan Univ Inst Comp Sci & Informat Engn Ilan Taiwan Natl Ilan Univ Dept Elect Engn Ilan Taiwan Natl Dong Hwa Univ Dept Elect Engn Hualien Taiwan

More people are studying digital video stream transference via networks. However, frequent Internet use increases the requirement for copyright protection and security. As a consequence, to prevent video streams that belong to rightful owners from being intentionally or unknowingly used by others, information protection is indispensable. The authors propose a novel method for video watermarking that is specifically designed for H.264 video. For the experiment, a low-energy signal can relatively guard against low-pass filter attacks. Conversely, a high-energy signal in the host signal can relatively guard against the high-frequency noise attack. In view of these facts, the proposed system design embedding algorithm provides high-energy and low-energy blocks. The blocks in the host image frame are divided into two different groups by estimating the block energy. The existing singular value decomposition methods were employed to calculate the watermark information. In order to enhance the security, the proposed system also employs torus automorphisms to encrypt the watermark. To achieve better robustness, the encrypted results use secret image sharing technology embedded into different I-frames in the video stream.

关键词： video streaming image denoising video coding digital video stream transference secret image sharing image and video coding copyright security low-pass filter attacks Data security singular value decomposition methods watermarking information protection SVD copyright protection high-frequency noise attack H.264 video watermarking video signal processing

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Compression of multi-polarimetric SAR intensity images based on 3D-matrix transform

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IET image PROCESSING 2008年第4期2卷 194-202页

作者： Zhang, W. -C. Wang, Y. -F. Hu, G. -H. Chinese Acad Sci Inst Elect Beijing 100080 Peoples R China Chinese Acad Sci Grad Sch Beijing 100039 Peoples R China

The algorithms for multi-polarimetric synthetic aperture radar (SAR) intensity image compression are investigated. First, the multi-polarimetric SAR intensity images (HH, HV and VV) are considered as a 3D-matrix unit, and then a 3D-matrix transform is adopted to remove the redundancies, which includes 1D discrete cosine transform (DCT) in the polarimetric channels and 2D discrete wavelet transform (DWT) in each polarimetric SAR image plane. After the 3D-matrix transform, two methods are proposed to encode the 3D mixed coefficients. One is a bit allocation encoding based on differential entropy and the other is a 3D set partitioning in hierarchical trees (SPIHT) encoding which is an improvement of the conventional SPIHT. The two methods can remove not only the redundancies of the image inside but also the redundancies among the polarimetric channels, because they do not process every channel image separately. Both the theory and experimental results show that the proposed methods are efficient.

关键词： SPIHT encoding polarimetric channels discrete cosine transforms 3D-matrix transform Radar equipment, systems and applications 3D set partitioning in hierarchical trees tree codes data compression 2D discrete wavelet transform image and video coding image coding Integral transforms DCT Algebra discrete wavelet transforms radar polarimetry matrix algebra images compression synthetic aperture radar multipolarimetric SAR intensity images DWT radar imaging discrete cosine transform 3D mixed coefficients differential entropy

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