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Coronary angiogram video compression using wavelet-based contourlet transform and region-of-interest technique

IET image PROCESSING 2012年第8期6卷 1049-1056页

作者： Selvi, G. Uma Vetri Nadarajan, R. PSG Coll Technol Dept Math & Comp Applicat Coimbatore 641004 Tamil Nadu India

In this study, the authors have proposed a new rapid method for the compression of coronary angiogram video sequences. The method is based on the philosophy that diagnostically significant areas of the image should be allocated the greatest proportion of the total allocated bit-budget. The approach uses a wavelet-based contourlet transform coder based on the set partitioned embedded block coder. Incorporated into this framework is a region-of-interest (ROI) detection technique. The combined result is an approach that removes the low-level contourlet coefficients for some diagnostically insignificant regions of the image in an extremely efficient manner. This allows additional bits to be used within the ROI to improve the quality of the significant areas. The results are compared for a number of real data sets and evaluated by trained cardiologists.

关键词： coronary angiogram video compression Patient diagnostic methods and instrumentation region-of-interest detection technique data compression Biology and medical computing image and video coding set partitioned embedded block coder low-level contourlet coefficients wavelet-based contourlet transform coder angiocardiography Integral transforms region-of-interest technique video coding image sequences ROI detection technique wavelet transforms video signal processing block codes medical image processing Biomedical measurement and imaging coronary angiogram video sequences

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Parametrisation construction frame of lifting scheme

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IET SIGNAL PROCESSING 2011年第1期5卷 1-15页

作者： Yang, X. Min, J. Shi, Y. Beihang Univ LMIB Minist Educ Dept Math Beijing 100191 Peoples R China

In this study, the authors propose a novel construction frame of lifting scheme, which includes corresponding filters design, theory analysis and application. By applying the presented frame, they can realise the lifting scheme of biorthogonal wavelets with prediction and updating filters that are of arbitrary odd or even length. The prediction and updating filters are built based on Bernstein bases and generalised Bernstein bases, which possess transforming characters of symmetry, required vanishing moments and flatness of passbands of frequency response. The authors further obtain a new family of biorthogonal wavelets and the related library of biorthogonal symmetric waveforms. By using the parametric filters, they can achieve the best transform possible aiming at image compression by adjusting the coefficients of the filters. The authors explore the applicability of the proposed transforms for image compression with high compression rates, and the results of the experiments show that the performance is comparable with CDF9/7.

关键词： Computer vision and image processing techniques image and video coding wavelet transforms updating filters image coding Bernstein bases generalised Bernstein bases biorthogonal wavelets frequency response Filtering methods in signal processing lifting scheme parametrisation construction frame prediction filters image compression filters design theory analysis Integral transforms biorthogonal symmetric waveforms filtering theory

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Motion vector generation for video coding by gray prediction

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IET COMPUTER VISION 2011年第1期5卷 14-22页

作者： Wu, Y. -G. Huang, G. -F. Chang Jung Christian Univ Dept Comp Sci & Informat Engn Tainan Taiwan Leader Univ Dept Comp Sci & Informat Engn Tainan Taiwan

An efficient prediction algorithm for motion vectors in video compression is proposed. Motion estimation is an important part in motion compensated video encoding system, which is used to eliminate the temporal redundancy in video sequence. Motion vectors dominate the quality of decoded video so that the generation of motion vectors is an important topic in video coding. Exhaustive block matching algorithm (EBMA) can get the optimal solution for motion vectors, but it takes much computational burden. In the proposed method, the authors use gray prediction to obtain the motion vectors. Gray prediction can predict the motion vectors quickly and accurately. Several video sequences are used to evaluate the performance in this study, and the experimental results show that the time that the proposed method needed is only 1.93% compared to EBMA and 11.75% compared to three steps searching algorithm whereas the degradation of PSNRY compared to EBMA is about 0.43 dB at most, which is almost invisible to human eyes.

关键词： motion vector generation PSNRY image and video coding Algebra EBMA video coding video sequence vectors computational burden video signal processing exhaustive block matching algorithm gray prediction motion estimation

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Moving target inverse synthetic aperture radar image resolution enhancement based on two-dimensional block sparse signal reconstruction

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IET image PROCESSING 2021年第13期15卷 3153-3159页

作者： He, Xingyu Tong, Ningning Liu, Tao Air Force Engn Univ Air Traff Control & Nav Coll Xian 710051 Shaanxi Peoples R China Air Force Engn Univ Air & Missile Def Coll Xian Shaanxi Peoples R China Air Force Engn Univ Teaching & Res Guarantee Ctr Xian Shaanxi Peoples R China

To achieve the high-resolution inverse synthetic aperture radar (ISAR) imaging of moving targets, the range Doppler method and compressed sensing technique can be used. However, those methods are generally faced with the problem of migration through range cells and basis mismatch problems, and the imaging results can be improved. To solve these problems and improve the image quality, the problem of ISAR imaging is termed as a block-sparse signal recovery problem by utilizing the block-sparse structure of the ISAR images. A localized low-rank promoting (LLP) method is introduced and extended to the complex case for the recovery of range compressed block-sparse signals. The sparse recovery problem is solved by minimizing another function, which is the surrogate function that can be solved more effectively. Based on the LLP method, the coefficients of the range compressed echo signal are reconstructed and some 2 x 2 matrices can be obtained. And then the log-determinant function is introduced to find the low rankness solutions for these matrices. Then the LLP method is also used in the cross-range domain to reconstruct the ISAR image. Experimental results show that the proposed method can recover better focused and higher quality ISAR images compared with the traditional methods.

关键词： image and video coding Radar equipment, systems and applications Optimisation techniques Interpolation and function approximation (numerical analysis)

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Automated region-based hybrid compression for digital imaging and communications in medicine magnetic resonance imaging images for telemedicine applications

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IET SCIENCE MEASUREMENT & TECHNOLOGY 2012年第4期6卷 247-253页

作者： Bairagi, V. K. Sapkal, A. M. Sinhgad Acad Engn Dept Elect & Telecom Engn Pune Maharashtra India Coll Engn Dept Elect & Telecom Engn Pune Maharashtra India

Many classes of images contains spatial regions which are more important than other regions. Compression methods which are capable of delivering higher reconstruction quality are attractive in this situation for the important parts. For the medical images, only a small portion of the image might be diagnostically useful, but the cost of a wrong interpretation is high. Hence, Region Based coding (RBC) technique is significant for medical image compression and transmission. Lossless compression in these 'regions' and lossy compression for rest of image can helps to achieve high efficiency and performance in telemedicine applications. This paper proposes an automated, efficient and low complexity, lossless, scalable RBC for Digital Imaging and Communications in Medicine (DICOM) images. The advantages of RBC are exploited in this paper, segmenting the region into various regions of importance and subjecting varying bit-rates for optimal performance. Moreover, the combined effects of Integer Wavelet Transform (IWT) and bit-rate limiting compression technique for lesser important regions helps reconstruct the image, reversibly, up to a desired quality. The overall compression thus reaches a satisfactory level to be able to safely transmit the image in limited bandwidth over a telemedicine network and reconstruct diagnostic details for treatment, most faithfully.

关键词： Computer vision and image processing techniques Biomedical magnetic resonance imaging and spectroscopy data compression image and video coding medical images Biology and medical computing wavelet transforms Biomedical communication automated region based hybrid compression digital imaging medicine magnetic resonance imaging image biomedical MRI telemedicine medical image compression image coding medical image processing lossless compression DICOM patient diagnosis integer wavelet transform Integral transforms in numerical analysis Patient diagnostic methods and instrumentation telemedicine applications region based coding technique image processing and restoration image transmission Function theory, analysis Medical magnetic resonance imaging and spectroscopy bit rate limiting compression technique

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Very-large-scale integration design of a low-power and cost-effective context-based adaptive variable length coding decoder for H.264/AVC portable applications

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IET image PROCESSING 2012年第2期6卷 104-114页

作者： Huang, H-J. Fang, C-H. Fan, C-P. Natl Chiao Tung Univ Dept Elect Engn Hsinchu 300 Taiwan Natl Chung Hsing Univ Dept Elect Engn Taichung 402 Taiwan

Context-based adaptive variable length coding (CAVLC) is a new and efficient entropy coding tool in H.264/AVC (advanced video coding). This study proposes a low-power and cost-effective CAVLC decoding architecture for the H.264/AVC baseline profile. Specifically, this study proposes an optimum two-layer power model for the variable length look-up table (VLUT) in the CAVLC decoder, and divides the decoding phase of the LUT into two-layer decoding to reduce power consumption. To achieve a cost-effective design, the proposed design merges common codewords to reduce the hardware cost among different LUTs in the second layer decoding. The proposed decoder is based on Taiwan Semiconductor Manufacturing Company (TSMC) 0.18 mu m CMOS technology, and was completely verified on a field-programmable gate array (FPGA) emulation platform. The proposed design meets the demands of the real-time CAVLC decoding and reduces power consumption by 44-48% more than previous low-power CAVLD schemes. Finally, the proposed low-power and cost-effective CAVLD design is suitable for H.264/AVC portable applications.

关键词： size 0.18 mum Codes table lookup variable length codes field programmable gate arrays image and video coding entropy codes CMOS technology context-based adaptive variable length coding decoder entropy coding tool common codewords adaptive codes Logic circuits video coding Logic and switching circuits cost-effective CAVLC decoding variable length look-up table advanced video coding H.264/AVC portable applications two-layer decoding decoding CMOS integrated circuits VLSI video signal processing Taiwan Semiconductor Manufacturing Company field programmable gate array low-power CAVLC decoding power consumption very large scale integration

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Forgery localization in images based on joint statistics of image blocks with neighbouring blocks

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IET image PROCESSING 2021年第9期15卷 1893-1908页

作者： Singhal, Divya Gupta, Abhinav Jaypee Inst Informat Technol Dept Elect & Commun Engn A-10Sect 62 Noida 201301 Uttar Pradesh India

Flawless image forensic analysis necessitates precise identification of tampering regions in digital images along with the determination of state of an image (original or forged). Most of the efforts towards localization of forgeries involve localization of information-changing forgeries with less focus towards localization of information-preserving forgeries. This paper proposes a new information-preserving forgery localization method to localize 10 different tampering types exploiting the fact that joint statistics of locally forged regions and neighbouring original regions is disturbed. The proposed 18-dimensional detector is trained using ensemble classifier for fine-grain identification of forged regions in post-JPEG compressed images and results are compared with two recent state-of-the-art detectors. The results demonstrate the effectiveness of the proposed detector with significant performance gain over existing detectors, particularly for localization in images that are compressed with low quality factors of compression.

关键词： Optical, image and video signal processing image and video coding Computer vision and image processing techniques

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Design of a context-adaptive variable length encoder for real-time video compression on reconfigurable platforms

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IET image PROCESSING 2012年第4期6卷 301-308页

作者： Licciardo, G. D. Albanese, L. Freda Univ Salerno Dept Elect & Informat Engn DIEII I-84084 Salerno Italy

In this study, a new context-adaptive variable length-coding encoder architecture is proposed particularly aimed to be implemented with field programmable logics (FPL) like FPGAs. The design implements different approaches in order to minimise the area cost as well as to speed up the coding efficiency, which allows real-time compression of 1080 p video streams coded in YCbCr 4:2:0 format. Priority cascading logics have been implemented in order to increase the parallelisation degree of the pre-coding stage, thus favouring the limitation of the number of clock cycles needed for the extraction of symbols from the input data, whereas the employment of the arithmetic table elimination technique has allowed a large-area reduction of the encoder thanks to the elimination of 18 of the 38 tables needed for the encoding stage. The design achieves real time elaboration with an operation frequency of 63 MHz and occupies 2200 look-up table (LUT)s when implemented on a low-cost, low-end XILINX Spartan 3 FPGA, thus overcoming the most recent FPL implementation and making this encoder quite comparable both in terms of area and speed with some recently proposed ASIC implementations, so that it turns out to be a valid alternative also for application specific implementations.

关键词： precoding parallelisation degree field programmable logics look-up table reconfigurable platform data compression table lookup variable length codes field programmable gate arrays FPL implementation Xilinx Spartan 3 real-time video compression coding efficiency priority cascading logics image and video coding precoding stage arithmetic table elimination technique low-end XILINX Spartan 3 FPGA Logic circuits Computer architecture video coding Logic and switching circuits clocks reconfigurable architectures YCbCr 4:2:0 format context-adaptive variable length-coding encoder architecture video signal processing video streaming length-coding encoder architecture symbols extraction clock cycle ASIC implementation

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Optimal model-based complexity control for H.264 video encoding

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IET image PROCESSING 2012年第1期6卷 60-71页

作者： Chien, M. -C. Chang, P. -C. Natl Cent Univ Dept Commun Engn Tao Yuan 320 Taiwan

An H.264 video encoder adopts multiple encoding tools to achieve high coding efficiency at the expense of high computational complexity. The allowable computational complexity for real-time video encoding, however, is generally limited in a wireless handset. This research proposes a complexity control mechanism that is composed of two algorithms to minimise the distortion of each encoded video frame under the computational complexity constraint and the rate constraint. The first proposed algorithm performs optimal complexity allocation among encoding tools based on a new complexity-rate-distortion (C-R-D) model. This model precisely describes how each encoding tool influences the C-R-D performance of the encoder with concise formulas. Accordingly, the algorithm obtains the optimal complexity of each encoding tool by a closed-form solution with small complexity overhead. Based on a new C-D model of motion estimation, this work proposes the second algorithm that performs optimal complexity allocation among macro-blocks to further allocate suitable complexity to each macro-block. Experiments performed on a software-optimised source code show that these two algorithms yield superior performance to the existing algorithms.

关键词： closed-form solution high computational complexity constraint H.264 video encoder wireless handset image and video coding motion estimation radiocommunication complexity-rate-distortion model H.264 video encoding optimal complexity allocation video coding real-time video encoding optimal model-based complexity control mechanism video signal processing Radio links and equipment high coding efficiency software-optimised source code communication complexity multiple encoding tools

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Colour image watermarking for tamper proofing and pattern-based recovery

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IET image PROCESSING 2012年第5期6卷 445-454页

作者： Liu, K. -C. Information Educating Center Taiwan Hospitality and Tourism College Taiwan

The rapid development of the internet allows digital media being easily delivered, copied and even tampered. The watermarking issue has thus focused mainly on the medium of authentication. In this study, an efficient self-embedding watermarking scheme for colour image authentication is proposed. The scheme is designed to achieve tamper proofing and high-quality recovery. The scheme is efficient because the validity of image blocks is simply proofed by using a dual-option parity-check method and morphological operations. The former is used to generate authentication information for obtaining better results of tamper proofing and the latter is used to further improve the neighbouring connectivity of the proofing results. To achieve high-quality recovery of the tampered image, the feature information of the host colour image and its corresponding block-edge-pattern information are properly organised to embed into three colour components of the host colour image. Meanwhile, the embedding information is appropriately distributed over luminance and chrominance components of the colour image in the YCbCr colour space such that the quality of the watermarked image can be better obtained. The simulation results show that the proposed watermarking scheme can effectively proof the tempered region with high detection rate and can restore the tempered region with high quality.

关键词： image colour analysis Internet Computer vision and image processing techniques tamper proofing image watermarking image and video coding image block validity image coding colour image authentication information high-quality pattern-based recovery high-quality recovery self-embedding watermarking scheme feature information dual-option parity-check method morphological operation digital media image sensors colour image watermarking Data security chrominance component luminance component block-edge-pattern information

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