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An improved symbol reduction technique based Huffman coder for efficient entropy coding in the transform coders

IET image PROCESSING 2021年第4期15卷 1008-1022页

作者： Thakur, Vikrant Singh Thakur, Kavita Gupta, Shubhrata Natl Inst Technol Dept Elect Engn Raipur 492001 Madhya Pradesh India Pt Ravishankar Shukla Univ SOS Elect & Photon Raipur Madhya Pradesh India

Entropy coding is the essential block of transform coders that losslessly converts the quantized transform coefficients into the bit-stream suitable for transmission or storage. Usually, the entropy coders exhibit less compression capability than the lossy coding techniques. Hence, in the past decade, several efforts have been made to improve the compression capability of the entropy coding technique. Recently, a symbol reduction technique (SRT) based Huffman coder is developed to achieve higher compression than the existing entropy coders at similar complexity of the regular Huffman coder. However, the SRT-based Huffman coding is not popular for the real-time applications due to the improper negative symbol handling and the additional indexing issues, which restrict its compression gain at most 10-20% over the regular Huffman coder. Hence, in this paper, an improved SRT (ISRT) based Huffman coder is proposed to properly alleviate the deficiencies of the recent SRT-based Huffman coder and to achieve higher compression gains. The proposed entropy coder is extensively evaluated on the ground of compression gain and the time complexity. The results show that the proposed ISRT-based Huffman coder provides significant compression gain against the existing entropy coders with lower time consumptions.

关键词： Codes image and video coding Computer vision and image processing techniques

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Scalable wavelet coding for synthetic/natural hybrid images

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR video TECHNOLOGY 1999年第2期9卷 244-254页

作者： Sodagar, I Lee, HJ Hatrack, P Zhang, YQ Sarnoff Corp Multimedia Technol Lab Princeton NJ 08512 USA

This paper describes the texture representation scheme adopted for MPEG-4 synthetic/natural hybrid coding (SNHC) of texture maps and images. The scheme is based on the concept of muitiscale zerotree wavelet entropy (MZTE) coding technique, which provides many levels of scalability layers in terms of either spatial resolutions or picture quality. MZTE, with three different modes (single-Q, multi-Q, and bilevel), provides much improved compression efficiency and fine-gradual scalabilities, which are ideal for hybrid coding of texture maps and natural images. The MZTE scheme is adopted as the baseline technique for the visual texture coding profile in both the MPEG-4 video group and SNHC group. The test results are presented in comparison with those coded by the baseline JPEG scheme for different types of input images, MZTE was also rated as one of the top five schemes in terms of compression efficiency in the JPEG2000 November 1997 evaluation, among 27 submitted proposals.

关键词： compression image and video coding JPEG-20001 MPEG-4 texture coding wavelet

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Closure of sets: a statistically hypersensitive system for steganalysis of least significant bit embedding

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IET SIGNAL PROCESSING 2011年第4期5卷 379-389页

作者： Khosravirad, S. R. Eghlidos, T. Ghaemmaghami, S. Sharif Univ Technol Elect Res Inst Tehran Iran

This study introduces a new scheme for steganalysis of the least significant bit (LSB) embedding, based on the idea of closure of sets (CoS), which is independent of the type of cover signal, applicable to both spatial and transform domains. The CoS is referred to as some special subsets that could be found in a common space whose elements relate to higher-order statistical properties of the signal. The proposed scheme is used for steganalysis of the LSB steganography of greyscale TIFF and JPEG images and audio signals, employing a set of accurate and monotone features that are extracted based on the CoS definition. It is shown that significant improvement to the detection accuracy in steganalysis is achieved using the proposed scheme, particularly at low embedding rates.

关键词： Computer vision and image processing techniques closure of sets Data security image and video coding steganography image coding Cryptography least significant bit embedding statistically hypersensitive system steganalysis feature extraction transforms spatial domain audio signals Speech and audio coding JPEG images audio coding transform domain greyscale TIFF images image colour analysis least significant bit steganography Integral transforms monotone feature extraction higher-order statistical property

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Two-dimensional ISAR model and image reconstruction with stepped frequency-modulated signal

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IET SIGNAL PROCESSING 2008年第3期2卷 277-290页

作者： Karakasiliotis, A. V. Lazarov, A. D. Frangos, P. V. Boultadakis, G. Kalognomos, G. Natl Tech Univ Athens Sch Elect & Comp Engn Div Informat Transmiss Syst & Mat Technol GR-15773 Zografos Greece Burgas Free Univ Burgas Bulgaria

A two-dimensional (2-D) inverse synthetic aperture radar (ISAR) return signal model that employs stepped frequency (SF) modulation is developed. The geometry of the examined ISAR scenario is described by analytical geometrical equations. The target to be imaged is represented by a rectangular grid of point scatterers, moving along a rectilinear trajectory at constant speed, without any rotational motion. Thus, the inverse synthetic aperture results from the translational motion of the target for a short period of time. The process of ISAR signal modelling through coherent summation of the SF-modulated signals reflected from different point scatterers of the target is thoroughly described. Moreover, an efficient ISAR image reconstruction approach, including cross-correlation-based range compression and fast-Fourier-transform-based azimuth compression, is presented through analytical mathematical expressions. Numerical simulations are carried out for various SF ISAR scenarios and high-resolution ISAR images are obtained by applying the proposed ISAR image reconstruction approach. Simulation results (ISAR images and corresponding entropy values) indicate the validity of the proposed 2-D SF ISAR return signal model and the efficiency of the proposed imaging algorithms. Finally, a numerical simulation result is illustrated, which shows the comparison of the performance of the proposed ISAR image reconstruction algorithms based on SF and linear frequency modulation waveforms. It is shown that the two waveforms attain almost the same ISAR image resolution.

关键词： Radar theory image coding rectangular grid image and video coding Modulation and coding methods ISAR return signal model image reconstruction rectilinear trajectory translational motion frequency modulation synthetic aperture radar radar imaging 2D ISAR model fast-Fourier-transform-based azimuth compression cross-correlation-based range compression inverse synthetic aperture radar ISAR signal modelling stepped frequency-modulated signal

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Adaptive rate control for Motion JPEG2000

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IET image PROCESSING 2009年第2期3卷 75-87页

作者： Li, L. Guo, M. Wang, Z. S. Chinese Acad Sci Comp Technol Inst Beijing 100190 Peoples R China Chinese Acad Sci Grad Univ Beijing 100049 Peoples R China

Rate and quality-constrained rate control is very effective for video applications, since it can maintain constant quality while eliminating local rate spikes. An adaptive rate control method based on image activity measures (ARCIAM) is proposed for Motion JPEG2000. The algorithm can efficiently adjust the compressed bit rates to meet the rate and quality constraints for different types of colour sequences. It predicts the rate-distortion (RD) slope thresholds for frames based on image activity measure (IAM) before entropy coding. Thus, the encoding of unnecessary coding passes can be avoided. Experimental results show that the proposed method can meet the quality and rate constraints, and can achieve quality performance comparable to post-compression rate distortion optimisation at the same bit rate. Under 3 bpp and 40 dB constraints, ARCIAM can reduce the total encoding time and tier-1 encoding time for sequences by more than 20 and 30%, respectively. Moreover, the memory requirement for buffering bit-streams and RD-slope information is reduced by more than 30% on average. Besides, the method can be incorporated into the line-based JPEG2000 encoding system easily, and has been implemented on Kakadu.

关键词： Motion JPEG2000 rate-distortion slope thresholds adaptive control image activity measure adaptive rate control method video coding image sequences image and video coding video applications image-video coding image activity measures entropy coding image colour analysis colour sequences line-based JPEG2000 encoding system video signal processing

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Security augmentation grounded on Fresnel and Arnold transforms using hybrid chaotic structured phase mask

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IET image PROCESSING 2021年第5期15卷 1042-1052页

作者： Yadav, Shivani Singh, Hukum NorthCap Univ Dept Appl Sci Sect 23-A Gurugram India

A novel asymmetric double image encryption technique is introduced to protect the algorithm from the interlopers by using hybrid chaotic structured phase masks in Arnold and Fresnel transforms. Mostly random phase masks are used routinely in many algorithms which are not strong against many attacks. So, taking in consideration replacing of random phase masks with the new hybrid chaotic structured phase masks takes place in the algorithm. With the assistance of Fresnel zone plates, radial Hilbert mask and logistic map functions, the chaotic structured phase mask is accumulated and hybrid chaotic structured phase mask provides extra security to system. Arnold transform helps in pixel shuffling, and with the pixel reorganization, it also helps in image reaping and bordering. The propagation distance of the Fresnel transform and the constraints of the Arnold transform serve as keys for encryption and decryption. To check the sturdiness of hybrid chaotic structured phase mask, simulations have been done which are carried out by the support of MATLAB R2018a (9.4.0.813654).

关键词： Cryptography image and video coding Integral transforms in numerical analysis Computer vision and image processing techniques Data security Integral transforms in numerical analysis

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Scene change detection algorithms for content-based video indexing and retrieval

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ELECTRONICS & COMMUNICATION ENGINEERING JOURNAL 2001年第3期13卷 117-126页

作者： Fernando, WAC Canagarajah, CN Bull, DR Asian Inst Technol Sch Adv Technol Klongluang 12120 Thailand Univ Bristol Image Commun Grp Bristol BS8 1UB Avon England Univ Bristol Ctr Commun Res Bristol BS8 1TH Avon England

There is an urgent need to extract key information from video automatically for the purposes of indexing, fast retrieval, and scene analysis. To support this vision, reliable scene change detection algorithms must be developed. Several algorithms have been proposed for both sudden and gradual scene change detection in uncompressed and compressed video. In this paper some common algorithms that have been proposed for scene change detection are reviewed. A novel algorithm for sudden scene change detection for MPEG-2 compressed video is then presented. This uses the number of interpolated macroblocks in B-frames to identify the sudden scene changes. A gradual scene change detection algorithm based on statistical features is also presented.

关键词： Information retrieval techniques retrieval Interpolation and function approximation (numerical analysis) gradual scene change detection data compression scene change detection algorithms content-based video indexing Information analysis and indexing compressed video uncompressed video B-frames scene analysis content-based retrieval video databases sudden scene change detection Other topics in statistics interpolation MPEG-2 compressed video image and video coding database indexing interpolated macroblocks Spatial and pictorial databases statistical features video signal processing video coding statistical analysis

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Fast and efficient lossless encoder in image compression with low computation and low memory

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IET image PROCESSING 2021年第11期15卷 2494-2507页

作者： Karthikeyan, N. Saravanakumar, N. M. Sivakumar, M. Anna Univ Dept CSE Sri Krishna Coll Engn & Technol Coimbatore Tamil Nadu India Anna Univ Dept CSE M Kumarasamy Coll Engn Karur India

This research focuses on frequency-based lossless new encoding technique with low computation and low memory scheme. This encoding technique doesn't require, any table similar to Huffman and Golomb Rice encoder, and doesn't take high computation time like an arithmetic encoder. For better comparative results, nearly 200 standard images were tested with the proposed encoder and their results were compared with the standard encoders. Based on the analysis of results reported in the experimental part, the proposed scheme in Discrete Cosine Transformation (DCT) achieves a high Compression Ratio (CR) of 97.68 %, Bits Per Pixel (BPP) of 0.19, Peak Signal To Noise Ratio (PSNR) of 27.62 dB for pepper image, CR of 98.65%, BPP of 0.11 and PSNR of 29.24 dB for house image, CR of 98.58 %, BPP of 0.11, PSNR of 30.59 dB for pepper image, CR of 98.37%, BPP of 0.13, PSNR of 31.37dB for house image in Discrete Wavelet Transformation (DWT) than compared to other encoders. It consumes less computation time to attain superior CR with a better quality of reconstructed picture than DCT based Huffman, Golomb- Rice (GR) coder and Low Complexity, Low memory Entropy Coder (LLEC), DWT based Arithmetic, GR code, LLEC.

关键词： image and video coding Computer vision and image processing techniques Integral transforms Integral transforms

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An image encryption algorithm with a plaintext-related quantisation scheme

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IET image PROCESSING 2021年第9期15卷 2039-2055页

作者： Oravec, Jakub Ovsenik, Lubos Papaj, Jan Tech Univ Kosice Fac Elect Engn & Informat Dept Elect & Multimedia Commun Nemcovej 32 Kosice 04001 Slovakia

This paper describes an image encryption algorithm that utilises a plaintext-related quantisation scheme. Various plaintext-related approaches from other algorithms are presented and their properties are briefly discussed. Main advantage of the proposed solution is the achievement of a similar behaviour like that of more complex approaches with a plaintext-related technique used in a rather simple step such as quantisation. This design should result in a favourable computational complexity of the whole algorithm. The properties of the proposal are evaluated by a number of commonly used numerical parameters. Also, the statistical properties of a pseudo-random sequence that is quantised according to the plain image pixel intensities are investigated by tests from NIST 800-22 suite. Obtained results are compared to values reported in related works and they imply that the proposed solution produces encrypted images with comparable statistical properties but authors' design is faster and more efficient.

关键词： Cryptography image and video coding Computer vision and image processing techniques Data security

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A pixel pair-based encoding pattern for stereo matching via an adaptively weighted cost

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IET image PROCESSING 2021年第4期15卷 908-917页

作者： Fu, Yuli Lai, Kaimin Chen, Weixiang Xiang, Youjun South China Univ Technol Sch Elect & Informat Engn Guangzhou Peoples R China

Stereo matching, which is a key problem in computer vision, faces the challenge of radiometric distortions. Most of the existing stereo matching methods are based on simple matching cost algorithms and appear the problem of mismatch under radiometric distortions. It is necessary to improve the robustness and accuracy of matching cost algorithms. A novel encoding pattern is proposed for stereo matching. In the proposed encoding pattern, each of the matching windows in the grey image and gradient images is divided into several isoline-like sets with different radii. Then, pixel pairs are defined in the isoline-like sets. An encoding function is used to decide the relative order between the two pixels in each pixel pair. To apply the pattern for matching cost computation and enhance the matching accuracy, an adaptively weighted cost is designed that is related to the isoline-like sets. Experiments are conducted on the Middlebury and KITTI data sets to show the validity of the proposed method under severe radiometric distortions. Also, the comparisons with some widely used methods are made in the experiments to illustrate the advantage of the proposed method.

关键词： image and video coding image recognition Computer vision and image processing techniques

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