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BAYESIAN ALGORITHMS FOR ADAPTIVE CHANGE DETECTION IN image SEQUENCES USING MARKOV RANDOM-FIELDS

SIGNAL PROCESSING-image COMMUNICATION 1995年第2期7卷 147-160页

作者： AACH, T KAUP, A RHEIN WESTFAL TH AACHEN INST COMMUN ENGND-52056 AACHENGERMANY

In many conventional methods for change detection, the detections are carried out by comparing a test statistic, which is computed locally for each location on the image grid, with a global threshold. These 'nonadaptive' methods for change detection suffer from the dilemma of either causing many false alarms or missing considerable parts of non-stationary areas. This contribution presents a way out of this dilemma by viewing change detection as an inverse, ill-posed problem. As such, the problem can be solved using prior knowledge about typical properties of change masks. This reasoning leads to a Bayesian formulation of change detection, where the prior knowledge is brought to bear by appropriately specified a priori probabilities. Based on this approach, a new, adaptive algorithm for change detection is derived where the decision thresholds vary depending on context, thus improving detection performance substantially. The algorithm requires only a single raster scan per picture and increases the computional load only slightly in comparison to non-adaptive techniques.

关键词： image ANALYSIS image coding CONTEXT-ADAPTIVE CHANGE DETECTION MARKOV RANDOM FIELDS

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Robust Blind Video Watermarking Against Geometric Deformations and Online Video Sharing Platform Processing

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IEEE TRANSACTIONS ON DEPENDABLE AND SECURE COMPUTING 2023年第6期20卷 4702-4718页

作者： He, Mingze Wang, Hongxia Zhang, Fei Abdullahi, Sani M. Yang, Ling Sichuan Univ Sch Cyber Sci & Engn Chengdu 610065 Sichuan Peoples R China Zhengzhou Xinda Inst Adv Technol Zhengzhou 450001 Henan Peoples R China China Three Gorges Univ Coll Comp & Informat Technol Yichang 443002 Hubei Peoples R China

In recent years, online video sharing platforms have been widely available on social networks. To protect copyright and track the origins of these shared videos, some video watermarking methods have been proposed. However, their robustness performance is significantly degraded under geometric deformations, which destroy the synchronization between the watermark embedding and extraction. To this end, we propose a novel robust blind video watermarking scheme by embedding the watermark into low-order recursive Zernike moments. To reduce the time complexity, we give an efficient computation method by exploring the characteristics of video and moments. The moment accuracy is greatly improved due to the introduction of a recursive computation method. Furthermore, we design an optimization strategy to enhance visual quality and reduce distortion drift of watermarked videos by analyzing the radial basis function. The robustness of the proposed scheme is verified by different attacks, including geometric deformations, length-width ratio changes, temporal synchronization attacks, and combined attacks. In practical applications, the proposed scheme effectively resists processing from video sharing platforms and screenshots taken with smartphones and PC monitors. The watermark is extracted without the host video. Experimental results show that our proposed scheme outperforms other state-of-the-art schemes in terms of imperceptibility and robustness.

关键词： Watermarking Strain Transforms Robustness Streaming media Resists image coding Robust video watermarking blind tracking origin zernike moments (ZMs)

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Multi-image encryption and authentication using computational ghost imaging and singular value decomposition

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IET image PROCESSING 2024年第13期18卷 3878-3891页

作者： Huang, Hong Han, ZhiGuang Hainan Univ Sch Informat & Commun Engn Haikou 570228 Hainan Peoples R China

The non-local imaging characteristics of computational ghost imaging (CGI) make it widely used in the field of information security. However, the information processing method based on traditional CGI has some problems in the process of multi-image encryption, such as low efficiency and unsatisfactory reconstruction quality. Therefore, this article proposes to use wavelet transform and singular value decomposition technology to help computational ghost imaging to efficiently complete the coding and encryption of multiple images, and use alternating direction multiplier method (ADMM) in the process of image restoration to carry out high-quality reconstruction of the original encrypted image. The results show that the scheme has good reconstruction effect, strong security and robustness even at a low sampling rate. It provides some reference for digital watermarking technology and cryptography. This article proposes a coding encryption and authentication scheme for multi-image information of computational ghost imaging using wavelet transform and singular value decomposition. Using ADMM optimization algorithm to reconstruct, the original image can be recovered with high quality even under low sampling rate. image

关键词： image coding image processing image reconstruction

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A CODEC FOR HDTV

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IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 1992年第3期38卷 325-340页

作者： NETRAVALI, A PETAJAN, E KNAUER, S FARYAR, AF KUSTKA, G MATTHEWS, K SAFRANEK, RJ AT and T Bell Laboratories Inc. Murray Hill NJ USA

A high quality digital video codec has been developed for the Zenith/AT&T HDTV system which adaptively selects between two transmission modes with differing rates and robustness. The codec works on an image progressively scanned with 1575 scan lines every 1/30th of a second and achieves a compression ratio of approximately 50 to 1. The high compression ratio facilitates robust transmission of the compressed HDTV signal within an NTSC taboo channel Transparent image quality is achieved using motion compensated transform coding coupled with a perceptual criterion to determine the quantization accuracy required for each transform coefficient. The codec has been designed to minimize complexity and memory in the receiver.

关键词： Codecs HDTV Decoding Redundancy Motion estimation Robustness image coding Video compression Design for disassembly Layout

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Multi-bit quantisation for similarity-preserving hashing

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IET COMPUTER VISION 2018年第5期12卷 616-622页

作者： Su, Liang Liang Tang, Jun Liang, Dong Zhu, Ming Anhui Univ Key Lab Intelligent Comp & Signal Proc Minist Educ Hefei 230601 Anhui Peoples R China Anhui Univ Sch Elect & Informat Engn Hefei 230601 Anhui Peoples R China

As a promising alternative to traditional search techniques, hashing-based approximate nearest neighbour search provides an applicable solution for big data. Most existing efforts are devoted to finding better projections to preserve the neighbouring structure of original data points in Hamming space, but ignore the quantisation procedure which may lead to the breakdown of the neighbouring structure maintained in the projection stage. To address this issue, the authors propose a novel multi-bit quantisation (MBQ) method using a Matthews correlation coefficient (MCC) term and a regularisation term. The authors' method utilises the neighbouring relationship and the distribution information of original data points instead of the projection dimension usually used in the previous MBQ methods to adaptively learn optimal quantisation thresholds, and allocates multiple bits per projection dimension in terms of the learned thresholds. Experiments on two typical image data sets demonstrate that the proposed method effectively preserves the similarity between data points in the original feature space and outperforms state-of-the-art quantisation methods.

关键词： quantisation (signal) cryptography search problems Big Data Hamming codes image segmentation learning (artificial intelligence) image coding multibit quantisation similarity-preserving hashing hashing-based approximate nearest neighbour search Big Data Hamming space MBQ method Matthews correlation coefficient MCC original data point distribution information multiple bits per projection dimension image data sets feature space

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Fast and low roundoff implementation of quadrature mirror filters for subband coding

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 1995年第6期5卷 524-532页

作者： Yang, JF Chan, DY Chen, YB Dept. of Electr. Eng. Nat. Cheng Kung Univ. Tainan Taiwan Department of Electrical Engineering National Cheng Kung University Tainan Taiwan

In this paper, me propose a fast and low roundoff-noise implementation of alias-free quadrature mirror filters (QMF's) for tree-structured subband coding, When N-tap FIR QMF's are directly utilized, they require 2N multiplications and 2(N - 1) additions to obtain a pair of high-band and low-band decimated outputs. Using recursive formulas and the polyphase concept, a QMF implementation is proposed that, for both analysis and synthesis stages, needs only (N/2 + 2) multiplications and (3N/2 + 8) additions to compute the same outputs. Furthermore, the proposed algorithm can reduce roundoff error when finite-wordlength processors are used to implement the encoder and decoder, Simulation examples for image coding are also given to demonstrate tire differences.

关键词： Mirrors Finite impulse response filter image coding Convolution Filtering algorithms Decoding HDTV Nonlinear filters Roundoff errors Computational modeling

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Sparse Gradient Regularized Deep Retinex Network for Robust Low-Light image Enhancement

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IEEE TRANSACTIONS ON image PROCESSING 2021年 30卷 2072-2086页

作者： Yang, Wenhan Wang, Wenjing Huang, Haofeng Wang, Shiqi Liu, Jiaying City Univ Hong Kong Dept Comp Sci Hong Kong Peoples R China Peking Univ Wangxuan Inst Comp Technol Beijing 100080 Peoples R China

Due to the absence of a desirable objective for low-light image enhancement, previous data-driven methods may provide undesirable enhanced results including amplified noise, degraded contrast and biased colors. In this work, inspired by Retinex theory, we design an end-to-end signal prior-guided layer separation and data-driven mapping network with layer-specified constraints for single-image low-light enhancement. A Sparse Gradient Minimization sub-Network (SGM-Net) is constructed to remove the low-amplitude structures and preserve major edge information, which facilitates extracting paired illumination maps of low/normal-light images. After the learned decomposition, two sub-networks (Enhance-Net and Restore-Net) are utilized to predict the enhanced illumination and reflectance maps, respectively, which helps stretch the contrast of the illumination map and remove intensive noise in the reflectance map. The effects of all these configured constraints, including the signal structure regularization and losses, combine together reciprocally, which leads to good reconstruction results in overall visual quality. The evaluation on both synthetic and real images, particularly on those containing intensive noise, compression artifacts and their interleaved artifacts, shows the effectiveness of our novel models, which significantly outperforms the state-of-the-art methods.

关键词： Lighting image restoration image enhancement image coding Noise reduction Atmospheric modeling Minimization Low-light enhancement Retinex model sparse gradient regularization residual dense network denoising

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Efficient morphological shape representation

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IEEE TRANSACTIONS ON image PROCESSING 1996年第1期5卷 89-101页

作者： Reinhardt, JM Higgins, WE PENN STATE UNIV DEPT ELECT ENGNUNIVERSITY PKPA 16802

Mathematical morphology is well suited to capturing geometric information, Hence, morphology-based approaches have been popular for object shape representation, The two primary morphology-based approaches-the morphological skeleton and the morphological shape decomposition (MSD)-each represent an object as a collection of disjoint sets, A practical shape representation scheme, though, should give a representation that is computationally efficient to use, Unfortunately, little work has been done for the morphological skeleton and the MSD to address efficiency. We propose a flexible search-based shape! representation scheme that typically gives more efficient representations than the morphological skeleton and MSD, Our method decomposes an object into a number of simple components based on homothetics of a set of structuring elements, To form the representation, the components are combined using set union and set difference operations, We use three constituent component types and a thorough cost-based search strategy to find efficient representations. We also consider allowing object representation error, which may yield even more efficient representations.

关键词： Shape Skeleton image reconstruction Morphology Humans Digital images image coding Pattern recognition image analysis Cancer

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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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A tutorial on modern lossy wavelet image compression: Foundations of JPEG 2000

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IEEE SIGNAL PROCESSING MAGAZINE 2001年第5期18卷 22-35页

作者： Usevitch, BE Univ Texas Dept Elect & Comp Engn El Paso TX 79968 USA

One of the purposes of this article is to give a general audiencesufficient background into the details and techniques of wavelet codingto better understand the JPEG 2000 standard. The focus is on thefundamental principles of wavelet coding and not the actual standarditself. Some of the confusing design choices made in wavelet coders areexplained. There are two types of filter choices: orthogonal andbiorthogonal. Orthogonal filters have the property that there are energyor norm preserving. Nevertheless, modern wavelet coders use biorthogonalfilters which do not preserve energy. Reasons for these specific designchoices are explained. Another purpose of this article is to compare andcontrast “early” wavelet coding with “modern”wavelet coding. This article compares the techniques of the modernwavelet coders to the subband coding techniques so that the reader canappreciate how different modern wavelet coding is from early waveletcoding. It discusses basic properties of the wavelet transform which arepertinent to image compression. It builds on the background material ingeneric transform coding given, shows that boundary effects motivate theuse of biorthogonal wavelets, and introduces the symmetric wavelettransform. Subband coding or “early” wavelet coding methodis discussed followed by an explanation of the EZW coding *** modern wavelet coders that extend the ideas found in the EZWalgorithm are also described

关键词： code standards filtering theory image coding linear phase filters telecommunication standards transform coding wavelet transforms EZW coding algorithm JPEG 2000 standard biorthogonal filters biorthogonal wavelets boundary effects early wavelet coding mod image compression wavelets filtering theory transform coding linear phase filters wavelet transforms border effects code standards image coding Data compression Modulo ENCODER biorthogonal wavelet wavelet coding biorthogonal filter

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