Motion Vector Difference Research Articles

High-security HEVC video steganography method using the motion vector prediction index and motion vector difference

High-security HEVC video steganography method using the motion vector prediction index and motion vector difference

A visual SLAM algorithm based on fuzzy clustering for removing dynamic features

Most visual simultaneous localization and mapping (SLAM) algorithms assume that no or only few moving objects occur in application environments. This assumption makes the algorithms vulnerable to the interference of moving objects in dynamic environments. To address the problem, a new visual SLAM method, which could eliminate dynamic features without any prior information, was proposed. By measuring the position of each feature point and its motion vector difference between image sequences, a two-stage clustering was performed on the feature points in the field of view. This method removed the features detected on moving objects, and used a static initialization technique to eliminate the dependence of SLAM on prior information. The proposed method intended to improve OV2SLAM (a fully online and versatile visual SLAM for real-time applications) algorithm, and the experimental verification was carried out. Our results show that while maintaining the real-time performance of the original OV2SLAM algorithm, the positioning accuracy and robustness of the proposed method is improved in a dynamic environment.

Improving deep learning-based video steganalysis with motion vector differences

Improving deep learning-based video steganalysis with motion vector differences

A Robust Selective Encryption Scheme for H.265/HEVC Video

To protect the information of video stream, many selective video encryption schemes have been proposed based on the H.265/HEVC video. However, most of the existing algorithms are not robust, thus failing to decrypt under packet loss. To further improve the robustness capability of video protection, a robust selective encryption scheme is proposed in this paper. In H.265/HEVC standard, video is encoded into multiple slices, and the slices are decoded independently. Inspired by the feature, each slice is individually encrypted using RC4 stream cipher. The pseudorandom binary sequence (PRBS) for one slice is related to encoding parameters and the SHA-256 hash value of the corresponding slice header, thus ensuring the real-time update of the PRBS and increasing the resistance to chosen-plaintext attack. Two-rounds shifting algorithm is designed to scramble non-zero coefficients of the transform units (TUs) and then motion vector difference (MVD) parameters, quantized transform coefficients (QTCs) and intra prediction modes (IPMs) are selected for encryption. The combination of coefficient scrambling and syntax elements encryption further improves the encryption performance. The proposed scheme is slice-synchronized. Hence, it decrypts normally in the case of packet loss, and supports online real-time interaction. Furthermore, the simulation and analysis results show that the proposed algorithm has format compatibility, high security and low time complexity, which is a promising tool for video cryptographic applications.

A Novel Separable Scheme for Encryption and Reversible Data Hiding

With the increasing emphasis on security and privacy, video in the cloud sometimes needs to be stored and processed in an encrypted format. To facilitate the indexing and tampering detection of encrypted videos, data hiding is performed in encrypted videos. This paper proposes a novel separable scheme for encryption and reversible data hiding. In terms of encryption method, intra-prediction mode and motion vector difference are encrypted by XOR encryption, and quantized discrete cosine transform block is permutated based on logistic chaotic mapping. In terms of the reversible data hiding algorithm, difference expansion is applied in encrypted video for the first time in this paper. The encryption method and the data hiding algorithm are separable, and the embedded information can be accurately extracted in both encrypted video bitstream and decrypted video bitstream. The experimental results show that the proposed encryption method can resist sketch attack and has higher security than other schemes, keeping the bit rate unchanged. The embedding algorithm used in the proposed scheme can provide higher capacity in the video with lower quantization parameter and good visual quality of the labeled decrypted video, maintaining low bit rate variation. The video encryption and the reversible data hiding are separable and the scheme can be applied in more scenarios.

Temporal Prediction Model-Based Fast Inter CU Partition for Versatile Video Coding.

Versatile video coding (VVC) adopts an advanced quad-tree plus multi-type tree (QTMT) coding structure to obtain higher compression efficiency, but it comes at the cost of a considerable increase in coding complexity. To effectively reduce the coding complexity of the QTMT-based coding unit (CU) partition, we propose a fast inter CU partition method based on a temporal prediction model, which includes early termination QTMT partition and early skipping multi-type tree (MT) partition. Firstly, according to the position of the current CU, we extract the optimal CU partition information of the position corresponding to the previously coded frames. We then establish a temporal prediction model based on temporal CU partition information to predict the current CU partition. Finally, to reduce the cumulative of errors of the temporal prediction model, we further extract the motion vector difference (MVD) of the CU to determine whether the QTMT partition can be terminated early. The experimental results show that the proposed method can reduce the inter coding complexity of VVC by 23.19% on average, while the Bjontegaard delta bit rate (BDBR) is only increased by 0.97% on average under the Random Access (RA) configuration.

Low‐latency selective encryption scheme for scalable extension of high‐efficiency video coding

AbstractThis article presents a selective encryption (SE) chaotic video stream cipher for the scalable extended high‐efficiency video coding (SHVC) bitstream. The proposed SHVC SE uses a logistic map (LM) for enciphering the motion vector difference (MVD), discrete cosine transform (DCT) coefficients and delta quantization parameter (dQP) sign bits. The SHVC SE chaotic video stream cipher is proposed to secure the most sensitive bits of the SHVC while keeping the video format compliance feature. Also, this paper presents a performance analysis for the proposed SHVC SE and the AES in CFB operation mode. Experimental results illustrate the main feature of using the LM in the proposed SHVC SE, which is lower latency encoding time for the SHVC SE chaotic video stream cipher than using the AES in CFB operation mode. Security investigations are performed on the proposed SHVC SE for ensuring the robustness of the ciphered SHVC digital video against unauthorized attacks.

Utilization of HEVC ChaCha20-Based Selective Encryption for Secure Telehealth Video Conferencing

Coronavirus (COVID-19) is a contagious disease that causes exceptional effect on healthcare organizations worldwide with dangerous impact on medical services within the hospitals. Because of the fast spread of COVID-19, the healthcare facilities could be a big source of disease infection. So, healthcare video consultations should be used to decrease face-to-face communication between clinician and patients. Healthcare video consultations may be beneficial for some COVID-19 conditions and reduce the need for face-to-face contact with a potentially positive patient without symptoms. These conditions are like top clinicians who provide remote consultations to develop treatment methodology and follow-up remotely, patients who consult about COVID-19, and those who have mild symptoms suggestive of the COVID-19 virus. Video consultations are a supplement to, and not a substitute for, telephone consultations. It may also form part of a broader COVID-19 distance care strategy that contains computerized screening, separation of possibly infectious patients within medical services, and computerized video-intensive observing of their intensive care that helps reduce mixing. Nowadays, the spread of the COVID-19 virus helps to expand the use of video healthcare consultations because it helps to exchange experiences and remote medical consultations, save costs and health procedures used to cope with the pandemic of the COVID-19 virus, and monitor the progress of treatment plans, moment by moment from a distance with precision, clarity and ease. From this perspective, this paper introduces a high-efficiency video coding (HEVC) ChaCha20-based selective encryption (SE) scheme for secure healthcare video Consultations. The proposed HEVC ChaCha20-based SE scheme uses the ChaCha20 for encrypting the sign bits of the Discrete Cosine Transform (DCT) and Motion Vector Difference (MVD) in the HEVC entropy phase. The main achievement of HEVC ChaCha20-based SE scheme is encrypting the most sensitive video bits with keeping low delay time, fixed bit rate of the HEVC, and format compliance. Experimental tests guarantee that the proposed HEVC ChaCha20-based SE scheme can ensure the confidentiality of the healthcare video consultations which has become easy to transmit through the internet.

Design and ARM-Based Implementation of Bitstream-Oriented Chaotic Encryption Scheme for H.264/AVC Video.

In actual application scenarios of the real-time video confidential communication, encrypted videos must meet three performance indicators: security, real-time, and format compatibility. To satisfy these requirements, an improved bitstream-oriented encryption (BOE) method based chaotic encryption for H.264/AVC video is proposed. Meanwhile, an ARM-embedded remote real-time video confidential communication system is built for experimental verification in this paper. Firstly, a 4-D self-synchronous chaotic stream cipher algorithm with cosine anti-controllers (4-D SCSCA-CAC) is designed to enhance the security. The algorithm solves the security loopholes of existing self-synchronous chaotic stream cipher algorithms applied to the actual video confidential communication, which can effectively resist the combinational effect of the chosen-ciphertext attack and the divide-and-conquer attack. Secondly, syntax elements of the H.264 bitstream are analyzed in real-time. Motion vector difference (MVD) coefficients and direct-current (DC) components in Residual syntax element are extracted through the Exponential-Golomb decoding operation and entropy decoding operation based on the context-based adaptive variable length coding (CAVLC) mode, respectively. Thirdly, the DC components and MVD coefficients are encrypted by the 4-D SCSCA-CAC, and the encrypted syntax elements are re-encoded to replace the syntax elements of the original H.264 bitstream, keeping the format compatibility. Besides, hardware codecs and multi-core multi-threading technology are employed to improve the real-time performance of the hardware system. Finally, experimental results show that the proposed scheme, with the advantage of high efficiency and flexibility, can fulfill the requirement of security, real-time, and format compatibility simultaneously.

Motion Vector Coding and Block Merging in the Versatile Video Coding Standard

This paper overviews the motion vector coding and block merging techniques in the Versatile Video Coding (VVC) standard developed by the Joint Video Experts Team (JVET). In general, inter-prediction techniques in VVC can be classified into two major groups: “whole block-based inter prediction” and “subblock-based inter prediction”. In this paper, we focus on techniques for whole block-based inter prediction. As in its predecessor, High Efficiency Video Coding (HEVC), whole block-based inter prediction in VVC is represented by adaptive motion vector prediction (AMVP) mode or merge mode. Newly introduced features purely for AMVP mode include symmetric motion vector difference and adaptive motion vector resolution. The features purely for merge mode include pairwise average merge, merge with motion vector difference, combined inter-intra prediction and geometric partitioning mode. Coding tools such as history-based motion vector prediction and bidirectional prediction with coding unit weights can be applied on both AMVP mode and merge mode. This paper discusses the design principles and the implementation of the new inter-prediction methods. Using objective metrics, simulation results show that the methods overviewed in the paper can jointly achieve 6.2% and 4.7% BD-rate savings on average with the random access and low-delay configurations, respectively. Significant subjective picture quality improvements of some tools are also reported when comparing the resulting pictures at same bitrates.

Cybersecurity framework of hybrid watermarking and selective encryption for secure HEVC communication

Recently, the digital multimedia cybersecurity has become a research topic of interest due to the fast development of real-time multimedia applications over public networks such as the Internet. Therefore, this research paper introduces an efficient cybersecurity framework for protecting the high-efficiency video coding (HEVC) frames. The suggested selective cybersecurity HEVC framework employs a robust hybrid technique based on watermarking and selective encryption for maintaining confidentiality and achieving copyright protection of the transmitted HEVC information. The watermarking method employs the Homomorphic transform and singular value decomposition in the discrete wavelet transform to increase the immunity of watermarked HEVC streams to attacks. Moreover, the selective encryption technique uses the Chaotic logistic map for encrypting the motion vector difference and the discrete cosine transform sign bits to provide the feature of HEVC format compliance with low encryption overhead cost. An extensive security investigation is carried out for the proposed selective HEVC cybersecurity framework. The obtained experimental outcomes ensure and validate the effectiveness of the selective HEVC cybersecurity framework for HEVC sequences transmission.

CUPSEED - A combined use of prediction syntax elements to embed data in SHVC video.

With the rapid advancement in digital technologies, video rises to become one of the most effective communication tools that continues to gain popularity and importance. As a result, various proposals are put forward to manage videos, and one of them is data embedding. Essentially, data embedding inserts data into the video to serve a specific purpose, including proof of ownership via watermark, covert communication in steganography, and authentication via fragile watermark. However, most conventional methods embed data by using only one type of syntax element defined in the video coding standard, which may suffer from large bit rate overhead, quality degradation, or low payload. Therefore, this work aims to explore the combined use of multiple prediction syntax elements in SHVC for the purpose of data embedding. Specifically, the intra prediction mode, motion vector predictor, motion vector difference, merge mode and coding block structure are collectively manipulated to embed data. The experimental results demonstrate that, in comparison to the conventional single-venue data embedding methods, the combined use of prediction syntax elements can achieve higher payload while preserving the perceptual quality with minimal bit rate variation. In the best case scenario, a total of 556.1 kbps is embedded into the video sequence PartyScene with a drop of 0.15 dB in PSNR while experiencing a bit rate overhead of 7.4% when all prediction syntax elements are utilized altogether. A recommendation is then put forward to choose specific types of syntax element for data embedding based on the characteristics of the video.

Novel video coding methods for versatile video coding

Versatile video coding (VVC), which is the next generation video coding standard, is being developed to provide greater coding efficiency than existing video coding standards. In VVC, various coding tools related to intra and inter prediction modes have been adopted. This paper introduces several methods that improve coding efficiency or reduce computational complexity on top of VVC adopted tools. The first method enhances the most probable mode list derivation with the statistics of the intra modes of neighbouring blocks. The second method reduces the number of contexts of the merge with motion vector difference mode. The third method excludes invalid block vector predictors early for the intra block copy mode to improve block vector coding. The experimental results show that the three proposed methods show coding efficiencies of −0.05% for all intra coding, −0.02% for random access, and −0.14% for random access coding scenarios, respectively.

Binary Code Optimized for Partial Encryption

A common technique for the partial encryption of compressed images and videos encrypts only the sign bits of some syntax elements such as the quantized transform coefficients or the motion vector differences. The sign bit can be interpreted as the most significant bit (MSB) in the binary representation of the syntax element. Our work is motivated by the key observation that the binary code used for this representation has an impact on the quality of the reconstruction at the eavesdropper and on the size of the stream to be encrypted. Therefore, we address the problem of optimal binary code design for partial encryption. Ideally, the goal is to simultaneously maximize the eavesdropper’s distortion and minimize the length of the compressed MSB stream. Since these two objectives are conflicting in general, we formulate the problem as the maximization of a weighted sum of the eavesdropper’s distortion and of the probability of the MSB being 0. We cast the problem as a binary integer linear program equivalent to a maximum weight matching problem, which has a polynomial-time solution algorithm. We show that when the source to be quantized and the quantizer are symmetric, the problem can be converted to a linear program of a smaller size, for a family of distortion metrics. Extensive experiments assess the performance of the optimized binary code in comparison with existing approaches. The results reveal that certain existing partial encryption schemes could benefit from the proposed design.

Efficient Privacy-Preserving Anomaly Detection and Localization in Bitstream Video

In cloud computing, videos may be in an encrypted format to protect privacy. Therefore, encrypted video processing is an important application in secure cloud computing. In this paper, we focus on parameter estimation and anomaly detection in an encrypted video bitstream. By analyzing the common properties of video encoding frameworks and the format-compliant encryption schemes, we propose an anomaly detection scheme for encrypted video bitstream with format-compliant encryption. From the encrypted bitstream, we extract three types of complementary features, i.e., the macroblock sizes, the macroblock partitions, and the motion vector difference magnitude, and then propose a method to combine these three features. The proposed detection and localization scheme does not involve video decryption, full decompression, or an interactive protocol, which makes it efficient. Our scheme is also compatible with different video encryption methods. To accelerate the running time, we develop a parallel implementation for our scheme. The experimental results show that our method achieves good running time and detection rate performance.

Efficient encryption technique for H.264/AVC videos based on CABAC and logistic map

Nowadays, the use of real time video communication is growing with a rapid pace. For example, Search and Rescue (SAR) applications like earthquake rescue, avalanche victims, wildfire monitoring in highway and surveillance are some of the applications of real time video communication. Most of these video communications require secure transmission of signals. For real time video communication, the processing time is considered as the most important metric to be optimized. Thus, finding a simple and time efficient encryption technique for securing the transmitted data becomes mandatory. The motive behind this work is to design a system that can process the video signal in real time providing a secure communication. In this paper, we present an efficient encryption technique which has low computation complexity. The proposed technique is based on Context-Adaptive Binary Arithmetic Coding (CABAC) where the bin-string of Intra-Prediction Mode, Motion Vector Difference (MVD) and residue coefficients are encrypted with the random behavior of chaotic systems. The random bit streams used for encryption are generated with chaotic systems using Logistic map. The experimental results show that the proposed technique is very effective for real-time applications and robust against different types of attacks.

Adaptive pattern selection strategy for diamond search algorithm in fast motion estimation

In this paper, an adaptive pattern selection strategy for diamond search (DS) algorithm is proposed. DS is one of state-of-the-art motion estimation algorithms, while the fixed search strategy and the singular termination strategy lead to lots of redundancy of search points. The proposed search strategy is based on the observation that more than 75% motion vector differences are around the initial predicted search centre in the range of 1. In our search strategy, small diamond search pattern and large diamond search pattern are adaptively used according to the distribution of motion vector differences and the matching error information of initial search centre. Our search strategy focuses on how to use small diamond search pattern and large diamond search pattern more efficiently than diamond search algorithm without introducing additional search patterns. Experimental results show that the proposed algorithm can save about 10.81 search points and achieve 0.12 dB higher PSNR on average compared to DS.

HEVC Selective Encryption Using RC6 Block Cipher Technique

The high efficiency video coding (HEVC) partial encryption (PE) technique depends on encrypting the highly sensitive data on the video bit stream. The HEVC PE technique should keep the video format compliance, should be of the same bit rate, and ensure real-time constraints. The paper suggests an effective RC6 HEVC PE technique which encrypts sensible video data bits with low complexity overhead, fast encoding time for real-time applications, and fixed HEVC bitrate. These features result from using the low computational complexity RC6 block cipher for encrypting the selective video bins. The proposed RC6 HEVC PE encrypts the discrete cosine transform (DCT) coefficients sign bit, the DCT remaining absolute values suffixes that are binarized by Exp-Golomb (EGk) order zero, the motion vector difference (MVD) sign bits, and MVD absolute values suffixes that are binarized by EGk order one. Also, this paper introduces experimental results that compare between the proposed RC6 HEVC PE and HEVC PE algorithms that use the Advanced Encryption Standard in different operation modes. This paper presents more details about the security analysis of RC6 HEVC PE including encryption quality test, key space test, statistical analysis such as histogram and correlation coefficient analysis, and sensitivity analysis such as the key sensitivity analysis. The achieved test results ensured and confirmed the security, reliability, and robustness of RC6 HEVC PE technique.

CABAC-based selective encryption for HEVC using RC6 in different operation modes

This paper proposes a selective encryption (SE) algorithm for the almost recently video compressing technique that is called High-Efficiency Video Coding (HEVC). The improvement of our HEVC SE algorithm is to secure real-time HEVC streaming using low computational overhead, same bit rate and ensuring the video format compliance. This contribution is achieved with low computational RC6 algorithm to encrypt subset of binstrings that is binarized using the bypass binary arithmetic coding mode in the context adaptive binary arithmetic coding (CABAC) process of HEVC. This binstrings subset is the non-zero discrete cosine transform (DCT) coefficients sign bits, motion vector difference (MVD) sign bits, remaining absolute values suffix of DCT, MVD absolute values suffix, Sample adaptive offset (SAO) sign bit, residual size, reference picture index and the delta Quantization Parameter (QP). Also, this paper investigates the performance evaluation of using the RC6 with its operation modes within the proposed HEVC CABAC SE. This investigation is done for choosing the best operation mode for RC6 to be suitable for being used in the HEVC real-time application. The security analysis like histogram analysis, correlation coefficients test and key sensitivity test are presented to make sure the protection of HEVC CABAC SE algorithm against brute force and statistical attacks. The performance analysis results prove that the HEVC CABAC SE is highly secure and can be used in real-time HEVC applications.

A Perceptual Encryption Scheme for HEVC Video with Lossless Compression

Aiming to protect the video content and facilitate online video consumption, a perceptual encryption scheme is proposed for high efficiency video coding (HEVC) video. Based on RC4 algorithm, a key stream generation method is constructed, whose proportion of “1” and “0” can be regulated. During HEVC encoding, four kinds of syntax elements including motion vector difference (MVD)' sign, MVD's amplitude, sign of the luma residual coefficient and sign of the chroma residual coefficient, are encrypted by the regulated key stream. Experimental results and analysis show that the proposed scheme has good perceptual protection for the video content, and some advantages such as low computational cost, format-compliance and no bitrate increase can be achieved. It provides an effective resolution for the paid video-on-demand services.