Recent Advances in Video Coding for Machines Standard and Technologies

To improve the performance of video compression for machine vision analysis tasks,a video coding for machines(VCM)standard working group was established to promote standardization procedures.In this paper,recent advances in video coding for machine standards are presented and comprehensive introductions to the use cases,requirements,evaluation frameworks and corresponding metrics of the VCM standard are given.Then the existing methods are presented,introducing the existing proposals by category and the research progress of the latest VCM conference.Finally,we give conclusions.

Large-scale video compression： recent advances and challenges

The evolution of social network and multimedia technologies encourage more and more people to generate and upload visual information, which leads to the generation of large-scale video data. Therefore, preeminent compression technologies are highly desired to facilitate the storage and transmission of these tremendous video data for a wide variety of applications. In this paper, a systematic review of the recent advances for large-scale video compression （LSVC） is presented. Specifically, fast video coding algorithms and effective models to improve video compression efficiency are introduced in detail, since coding complexity and compression efficiency are two important factors to evaluate video coding approaches. Finally, the challenges and fu- ture research trends for LSVC are discussed.

3D Perception Algorithms: Towards Perceptually Driven Compression of 3D Video

In this paper, we summarize 3D perception-oriented algorithms for perceptually driven 3D video coding. Several perceptual ef- fects have been exploited for 2D video viewing; however, this is not yet the case for 3D video viewing. 3D video requires depth perception, which implies binocular effects such as con fl icts, fusion, and rivalry. A better understanding of these effects is necessary for 3D perceptual compression, which provides users with a more comfortable visual experience for video that is de- livered over a channel with limited bandwidth. We present state-of-the-art of 3D visual attention models, 3D just-notice- able difference models, and 3D texture-synthesis models that address 3D human vision issues in 3D video coding and trans-mission.

Very Low Bit-Rate Video Coding Based on Wavelet Transform

Two video coding schemes based on wavelet transform achieving very low bit rate are presented in this paper. The first is a hybrid motion compensated wavelet transform(MC WT)system which behaves better at very low bit rates than the block DCT residual coder. The second is a new efficient coding system based on a simple frame differencing wavelet transform(FD WT)which performs well in both PSNR and visual quality with substantially reduced complexity.

Suitability of VVC and HEVC for Video Telehealth Systems

Video compression in medical video streaming is one of the key technologies associated with mobile healthcare.Seamless delivery of medical video streams over a resource constrained network emphasizes the need of a video codec that requires minimum bitrates and maintains high perceptual quality.This paper presents a comparative study between High Efciency Video Coding(HEVC)and its potential successor Versatile Video Coding(VVC)in the context of healthcare.A large-scale subjective experiment comprising of twenty-four non-expert participants is presented for eight different test conditions in Full High Denition(FHD)videos.The presented analysis highlights the impact of compression artefacts on the perceptual quality of HEVC and VVC processed videos.Our results and ndings show that VVC clearly outperforms HEVC in terms of achieving higher compression,while maintaining high quality in FHD videos.VVC requires upto 40%less bitrate for encoding an FHD video at excellent perceptual quality.We have provided rate-quality curves for both encoders and a degree of overlap across both codecs in terms of perceptual quality.Overall,there is a 71%degree of overlap in terms of quality between VVC and HEVC compressed videos for eight different test conditions.

3-D Wavelet Transform for Very Low Bit-Rate Video Coding

A new improved Goh's 3 D wavelet transform(WT) coding scheme is presented in this paper. The new scheme has great advantages including a simple code structure, low computation cost and good performance in PSNR, compression ratios and visual quality of reconstructions, when compared to the other existing 3 D WT coding methods and the 2 D WT based coding methods. The new 3 D WT coding scheme is suitable for very low bit rate video coding.

High-Efficiency Video Coder in Pruned Environment Using Adaptive Quantization Parameter Selection

The high-efficiency video coder(HEVC)is one of the most advanced techniques used in growing real-time multimedia applications today.However,they require large bandwidth for transmission through bandwidth,and bandwidth varies with different video sequences/formats.This paper proposes an adaptive information-based variable quantization matrix(AIVQM)developed for different video formats having variable energy levels.The quantization method is adapted based on video sequence using statistical analysis,improving bit budget,quality and complexity reduction.Further,to have precise control over bit rate and quality,a multi-constraint prune algorithm is proposed in the second stage of the AI-VQM technique for pre-calculating K numbers of paths.The same should be handy to selfadapt and choose one of the K-path automatically in dynamically changing bandwidth availability as per requirement after extensive testing of the proposed algorithm in the multi-constraint environment for multiple paths and evaluating the performance based on peak signal to noise ratio(PSNR),bit-budget and time complexity for different videos a noticeable improvement in rate-distortion(RD)performance is achieved.Using the proposed AIVQM technique,more feasible and efficient video sequences are achieved with less loss in PSNR than the variable quantization method(VQM)algorithm with approximately a rise of 10%–20%based on different video sequences/formats.

An Introduction to High Efficiency Video Coding Range Extensions

High Efficiency Video Coding (HEVC) is the latest international video coding standard, which can provide the similar quality with about half bandwidth compared with its predecessor, H.264/MPEG?4 AVC. To meet the requirement of higher bit depth coding and more chroma sampling formats, range extensions of HEVC were developed. This paper introduces the coding tools in HEVC range extensions and provides experimental results to compare HEVC range extensions with previous video coding standards. Ex?perimental results show that HEVC range extensions improve coding efficiency much over H.264/MPEG?4 AVC High Predictive profile, especially for 4K sequences.

Efficient and High Accuracy 2-D DCT and IDCT Architecture for Image Compression Based on Improved CORDIC

Discrete Cosine Transform(DCT)is the most widely used technique in image and video compression.In this paper,the structure of DCT and Inverse DCT(IDCT)algorithm is split in the form of COordinate Rotation DIgital Computer(CORDIC)rotation matrix.The two-dimensional(2-D)8×8 DCT/IDCT units based on the improved rotation CORDIC algorithm is proposed.The shift and addition operations of the CORDIC algorithm are used to replace the cosine multiplication operations in the algorithm.The design does not contain any multiplier unit,which reduces the complexity of the hardware unit.The row-column transform unit composed of register arrays connects two 1-D 8-point DCT units to complete the calculation of 2-D 8×8 DCT.The pipeline latency of proposed architecture is 28 clock cycles.The proposed efficient two-dimensional DCT architecture has been synthesized on the Xilinx’s Kintex-7 FPGA.The resource utilization is 17.36%for Slice LUTs,3.49%for Slice Registers,and the maximum operating frequency is 172 MHz.It takes only 0.161μs to complete a process of block of 8×8 samples.A frame of image is processed by the designed DCT unit and then reconstructed by the IDCT unit to verify the function.The Peak Signal to Noise Ratio(PSNR)can reach 51.99 dB.

Real-time and Automatic Close-up Retrieval from Compressed Videos

This paper proposes a thorough scheme, by virtue of camera zooming descriptor with two-level threshold, to automatically retrieve close-ups directly from moving picture experts group （MPEG） compressed videos based on camera motion analysis. A new algorithm for fast camera motion estimation in compressed domain is presented. In the retrieval process, camera-motion-based semantic retrieval is built. To improve the coverage of the proposed scheme, close-up retrieval in all kinds of videos is investigated. Extensive experiments illustrate that the proposed scheme provides promising retrieval results under real-time and automatic application scenario.

Video Compressed Sensing Reconstruction Based on Multi-Dimensional Reference Frame Multi Hypothesis Rediction

In this paper,a video compressed sensing reconstruction algorithm based on multidimensional reference frames is proposed using the sparse characteristics of video signals in different sparse representation domains.First,the overall structure of the proposed video compressed sensing algorithm is introduced in this paper.The paper adopts a multi-reference frame bidirectional prediction hypothesis optimization algorithm.Then,the paper proposes a reconstruction method for CS frames at the re-decoding end.In addition to using key frames of each GOP reconstructed in the time domain as reference frames for reconstructing CS frames,half-pixel reference frames and scaled reference frames in the pixel domain are also used as CS frames.Reference frames of CS frames are used to obtain higher quality assumptions.Themethod of obtaining reference frames in the pixel domain is also discussed in detail in this paper.Finally,the reconstruction algorithm proposed in this paper is compared with video compression algorithms in the literature that have better reconstruction results.Experiments show that the algorithm has better performance than the best multi-reference frame video compression sensing algorithm and can effectively improve the quality of slowmotion video reconstruction.

Novel block-matching algorithms by subsampling both search candidates and pixels

A new faster block-matching algorithm （BMA） by using both search candidate and pixd sulzsamplings is proposed. Firstly a pixd-subsampling approach used in adjustable partial distortion search （APDS） is adjusted to visit about half points of all search candidates by subsampling them, using a spiral-scanning path with one skip. Two sdected candidates that have minimal and second minimal block distortion measures are obtained. Then a fine-tune step is taken around them to find the best one. Some analyses are given to approve the rationality of the approach of this paper. Experimental results show that, as compared to APDS, the proposed algorithm can enhance the block-matching speed by about 30% while maintaining its MSE performance very close to that of it. And it performs much better than many other BMAs such as TSS, NTSS, UCDBS and NPDS.

Optimal Mode Decision Method for Interframe Prediction in H.264/AVC

Studies show that encoding technologies in H.264/AVC,including prediction and conversion,are essential technologies.However,these technologies are more complicated than the MPEG-4,which is a standard method and widely adopted worldwide.Therefore,the amount of calculation in H.264/AVC is significantly up-regulated compared to that of the MPEG-4.In the present study,it is intended to simplify the computational expenses in the international standard compression coding system H.264/AVC for moving images.Inter prediction refers to the most feasible compression technology,taking up to 60%of the entire encoding.In this regard,prediction error and motion vector information are proposed to simplify the computation of inter predictive coding technology.In the initial frame,motion compensation is performed in all target modes and then basic information is collected and analyzed.After the initial frame,motion compensation is performed only in the middle 8×8 modes,and the basic information amount shifts.In order to evaluate the effectiveness of the proposed method and assess the motion image compression coding,four types of motion images,defined by the international telecommunication union(ITU),are employed.Based on the obtained results,it is concluded that the developed method is capable of simplifying the calculation,while it is slightly affected by the inferior image quality and the amount of information.

Chest Compression Rate Measurement from Smart Phone Video

Out-of-hospital cardiac arrest is a life threatening situation where the first person performing car-diopulmonary resuscitation (CPR) most often is a bystander without medical training. Some existing smart phone apps can call the emergency number and provide for example global positioning system (GPS) loca-tion by the Norwegian air ambulance. To extend functionality of such apps by using the built in camera in a smart phone to capture video of the CPR performed, primarily to estimate the duration and rate of the chest compression executed.

Compressed Digital Video:Accelerating the Video Communications Revolution

Video is used across a range of applicaticos,from low data-rate mdeo telephony to digitalbroadcast high deftnuzontelevision. Since all applications in thts range require that digually represent-ed sequece of images be reduced in let-rtue for efficient transmision or strage, all applications can uli-lize the same core compression technology. CLI has spent nearl two decades advancing the quality andapplication of digitof video technolegy and continues to rvaluaie meny video compression techniques in-cluding fractof coding, mavelets, subband coding, the discreie cisine transform (DCT), and vectorquantization. CLI currently has concluded that the discrete cosine transform (DCT) combined with mo-tion compensation provides the best pictrue quality for a wide range of video applicarions. In face, theDCT is the technology used by telecommunicationscomputer, and consumer video standards such as H.261 ,JPEG ,adn MPEG. This paper reviews these and other digital video compression iechnologies andthen discusses how CLI applies them to dtfferent video applications. Even within standardsbased mar-kets such as that for MPEG video ditribution syuerns, different products are differentiated easily bydifferences between their proprietary methods for preprocessing ,coding mode selection, postprocessing,etc.

Composite Chaotic Pseudo-Random Sequence Encryption Algorithm for Compressed Video

Stream cryptosystems, which implement encryption by selecting parts of the block data and header information of the compressed video stream, achieve good real-time encryption with high flexibility. Chaotic random number generator-based approaches, for example, logistics maps, are comparatively promising approachs, but are vulnerable to attacks by nonlinear dynamic forecasting. A composite chaotic cryptography scheme was developed to encrypt the compressed video with the logistics map with a Z(2311) field linear congruential algorithm to strengthen the security of the mono-chaotic cryptography. The scheme maintained real-time performance and flexibility of the chaotic sequence cryptography. The scheme also in-tegrated asymmetrical public-key cryptography and encryption and identity authentification of control pa-rameters at the initialization phase. Encryption is performed in a layered scheme based on the importance of the data in a compressed video stream. The composite chaotic cryptography scheme has the advantage that the value and updating frequency of the control parameters can be changed online to satisfy the net-work requirements and the processor capability, as well as the security requirements. Cryptanalysis shows that the scheme guarantees robust security,provides good real-time performance,and has flexible im-plementation. Statistical evaluations and tests verify that the scheme is effective.

Chaos-Based Encryption Algorithm for Compressed Video

Encryption for compressed video streams has attracted increasing attention with the exponential growth of digital multimedia delivery and consumption. However, most algorithms proposed in the literature do not effectively address the peculiarities of security and performance requirements. This paper presents a chaos-based encryption algorithm called the chaotic selective encryption of compressed video (CSECV) which exploits the characteristics of the compressed video. The encryption has three separate layers that can be selected according to the security needs of the application and the processing capability of the client computer. The chaotic pseudo-random sequence generator used to generate the key-sequence to randomize the important fields in the compressed video stream has its parameters encrypted by an asymmetric cipher and placed into the stream. The resulting stream is still a valid video stream. CSECV has significant advantages over existing algorithms for security, decryption speed, implementation flexibility, and error preservation.

A Novel Method to Get Super-Resolution Images from Low-Resolution Compressed Video

In order to resolve the problems of discontented restoration effect and confined applying scope which exist in the current compressed video restoration algorithms, a novel method to get super-resolution images from low-resolution compressed video is proposed in this paper. At first, a uniform model is presented and the restoration problem in the Bayesian framework is formulated under the MAP criterion, then the focus is put on the hybrid motion-compensation and transform coding schemes, at last the methods of getting the parameters are provided. The results of the simulation clearly demonstrate that our method not only has the properties of finer vision effect and wider applying scope, but also performs better than those of current classical algorithms in the aspects of Peak Signal Noise Ratio （PSNR） under the basis of the same condition.