A Survey on Video Transmission Techniques
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paper_title: Macroblock layer rate control algorithm of H.264/AVC

paper_content:

A new macroblock layer rate control algorithm was proposed based on a relatively simpler rate-distortion(R-D) model in order to reduce the computational complexity and improve the efficiency of H.264/AVC encoder.The algorithm adopted an adaptive method of bit allocation and encoding complexity regulation.Comparing to the previous algorithms used the predicted value of mean of absolute difference(MAD) in bit allocation and parameters update,the new algorithm made full use of the actual MAD and the similarity of encoding mode between two successive frames to ensured the smoothness of the output bit rate and the quality of the decoded picture.A skipped-mode pre-decision method was also proposed to further decrease the computational complexity.Experimental results showed that the proposed algorithm increased the encoding speed by about 10% in average while maintaining the similar peak signal-to-noise ratio(PSNR) and bit rate performance compared with the algorithm adopted in JVT-G012.
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paper_title: A new rate control scheme using quadratic rate distortion model

paper_content:

A new rate control scheme is used to calculate the target bit rate for each frame based on a quadratic formulation of the rate distortion function. The distortion measure are assumed to be either the average quantization scale of a frame or mean square error. The rate distortion function is modeled as a second order function of the inverse of the distortion measure. We presented a closed form solution for the target bit allocation which applies to both the digital storage media (DSM) applications (e.g., MPEG-2) and very low bit rate (VLBR) applications (e.g., MPEG-4). We perform experiments on a wavelet-based coder to demonstrate the versatility of our scheme. Model parameters are estimated using statistical linear regression analysis. Since the estimation uses the past encoded frames of the same picture prediction type (I, P and B pictures), the proposed approach is a single pass rate control technique. For the MPEG-2 coder the fluctuations of the bit counts are significantly reduced by 20 percent to 65 percent in the standard deviation of the bit count while the picture quality remains the same. For the MPEG-4 VM coder, the PSNR is improved by almost one dB as compared to the best MPEG-4 VM rate control using exhaustive combinations of quantization scale parameters.
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paper_title: Improved frame-layer rate control for H.264 using MAD ratio

paper_content:

In recent years, rate control plays an increasing important role in real-time video communication applications using MPEG-4 AVC/H.264. An important step in many existing rate control algorithms, which employs the quadratic rate-distortion (R-D) model, is to determine the target bits for each P frame. This paper aims in improving video distortion, due to high motions or scene changes, by more accurately predicting frame complexity using the statistics of previously encoded frames. We use mean absolute difference (MAD) ratio as a measure for global frame encoding complexity. Bit budget is allocated to frames according to their MAD ratio, combined with the bits computed based on their buffer status. Simulation results show that the H.264 coder, using our proposed algorithm with virtually little computational complexity added, effectively alleviates PSNR surges and sharp drops for frames caused by high motions or scene changes.
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paper_title: Efficient Rate Control Schemes for H.264/AVC

paper_content:

In this work,a novel coding characteristics prediction scheme is presented to improve R-D modeling,by exploiting spatio-temporal correlations.Two different approaches to the problem of optimum bit allocation at a macroblock-by-macroblock basis are achieved,one of which is developed on a modified MPEG-4 Q2 rate model and the other on a linear rate model.Extensive experiments show that the linear scheme is a bit more accurate than the quadratic one while they achieve similar coding performance.It's also shown that both the two schemes significantly exceed JVT G012,the current standardized RC scheme.
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paper_title: Improved frame-layer rate control for H.264 using MAD ratio

paper_content:

In recent years, rate control plays an increasing important role in real-time video communication applications using MPEG-4 AVC/H.264. An important step in many existing rate control algorithms, which employs the quadratic rate-distortion (R-D) model, is to determine the target bits for each P frame. This paper aims in improving video distortion, due to high motions or scene changes, by more accurately predicting frame complexity using the statistics of previously encoded frames. We use mean absolute difference (MAD) ratio as a measure for global frame encoding complexity. Bit budget is allocated to frames according to their MAD ratio, combined with the bits computed based on their buffer status. Simulation results show that the H.264 coder, using our proposed algorithm with virtually little computational complexity added, effectively alleviates PSNR surges and sharp drops for frames caused by high motions or scene changes.
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paper_title: A Rate Control Algorithm for Scalable Video Coding

paper_content:

The joint scalable video model(JSVM)as a scalable extension of H.264/AVC provides a high efficient solution for scalable video coding(SVC).However,there is not efficient rate control scheme is specified.This paper presents a new rate control scheme for the JSVM based on the special structure of hierarchical B decomposition(or motion compensation temporal filtering(MCTF)).In a sense of bit allocation,a novel hierarchical bit allocation strategy is proposed.Meanwhile,the different rate-distortion(R-D)model is provided for each kind picture with different picture type or temporal decomposition level.Experiment results show that the mismatch of target bit rate and real bit rate generated for coding doesn't exceed 2%;meanwhile,the PSNR improvement can be up to 1dB in low bit rate;furthermore,comparing to the original rate control method which achieves the target bit rate through regulating quantization parameter(QP)step by step,the computation complexity of the proposed rate control algorithm base on experimental model is reduced drastically.
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paper_title: Accurate Distortion Estimation and Optimal Bandwidth Allocation for Scalable H.264 Video Transmission Over MIMO Systems

paper_content:

In this paper, we propose an optimal strategy for the transmission of scalable video over packet-based multiple-input multiple-output (MIMO) systems. The scalable extension of H.264/AVC that provides a combined temporal, quality and spatial scalability is used. For given channel conditions, we develop a method for the estimation of the distortion of the received video and propose different error concealment schemes. We show the accuracy of our distortion estimation algorithm in comparison with simulated wireless video transmission with packet errors. In the proposed MIMO system, we employ orthogonal space-time block codes (O-STBC) that guarantee independent transmission of different symbols within the block code. In the proposed constrained bandwidth allocation framework, we use the estimated end-to-end decoder distortion to optimally select the application layer parameters, i.e., quantization parameter (QP) and group of pictures (GOP) size, and physical layer parameters, i.e., rate-compatible turbo (RCPT) code rate and symbol constellation. Results show the substantial performance gain by using different symbol constellations across the scalable layers as compared to a fixed constellation.
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paper_title: Reliable Visual Transmission Method Combining Source Statistics and Network Congestion Control

paper_content:

An algorithm combining source statistics and network congestion control for robust video transmission over wireless network is proposed in this paper.Based on scene modeling and characteristic analyzing,all layers generated by scalable coding are classified into several types and two queuing are made respectively according to their contribution to network congestion and to the quality of reconstructed video.Then the source rate,unequal error protection level and congestion control strategy are dynamically adjusted according to different network status in which the packet loss is caused by network congestion or by unreliable transmission in wireless channel.The simulation results show that the proposed method can achieve better results than MPEG-4 video source coding with fixed rate Turbo coding and than the one which dynamically adjusting source coding and channel coding rates and using network congestion control method of selectively dropping I,B or P packets.
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paper_title: Wireless video surveillance system based on H.264 and 3G technology and optimized rate control algorithm

paper_content:

As the demand for network video surveillance equipment,this paper designed and realized the wireless video surveillance system based on 3G and H.264 technology.The system integrated video compression,embedded systems and wireless communications and related technologies.As the rate control algorithm of H.264 emphasis too much on versatility without taking into account about the high error rate of wireless networks,and with limited processing power of embedded terminals,the system optimized rate control algorithm of H.264 to fit these conditions.Experimental results show that there is no significant increase in the coded bits,but the image PSNR value has increased,and thus achieves a better rate control effect.
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paper_title: Multiple Description Coding: Compression Meets the Network

paper_content:

This article focuses on the compressed representations of pictures. The representation does not affect how many bits get from the Web server to the laptop, but it determines the usefulness of the bits that arrive. Many different representations are possible, and there is more involved in their choice than merely selecting a compression ratio. The techniques presented represent a single information source with several chunks of data ("descriptions") so that the source can be approximated from any subset of the chunks. By allowing image reconstruction to continue even after a packet is lost, this type of representation can prevent a Web browser from becoming dormant.
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paper_title: Error concealment for video transmission with dual multiscale Markov random field modeling

paper_content:

A novel error concealment algorithm based on a stochastic modeling approach is proposed as a post-processing tool at the decoder side for recovering the lost information incurred during the transmission of encoded digital video bitstreams. In our proposed scheme, both the spatial and the temporal contextual features in video signals are separately modeled using the multiscale Markov random field (MMRF). The lost information is then estimated using maximum a posteriori (MAP) probabilistic approach based on the spatial and temporal MMRF models; hence, a unified MMRF-MAP framework. To preserve the high frequency information (in particular, the edges) of the damaged video frames through iterative optimization, a new adaptive potential function is also introduced in this paper. Comparing to the existing MRF-based schemes and other traditional concealment algorithms, the proposed dual MMRF (DMMRF) modeling method offers significant improvement on both objective peak signal-to-noise ratio (PSNR) measurement and subjective visual quality of restored video sequence.
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paper_title: Robust Video Transmission With Distributed Source Coded Auxiliary Channel

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We propose a novel solution to the problem of robust, low-latency video transmission over lossy channels. Predictive video codecs, such as MPEG and H.26x, are very susceptible to prediction mismatch between encoder and decoder or ldquodriftrdquo when there are packet losses. These mismatches lead to a significant degradation in the decoded quality. To address this problem, we propose an auxiliary codec system that sends additional information alongside an MPEG or H.26x compressed video stream to correct for errors in decoded frames and mitigate drift. The proposed system is based on the principles of distributed source coding and uses the (possibly erroneous) MPEG/H.26x decoder reconstruction as side information at the auxiliary decoder. The distributed source coding framework depends upon knowing the statistical dependency (or correlation) between the source and the side information. We propose a recursive algorithm to analytically track the correlation between the original source frame and the erroneous MPEG/H.26x decoded frame. Finally, we propose a rate-distortion optimization scheme to allocate the rate used by the auxiliary encoder among the encoding blocks within a video frame. We implement the proposed system and present extensive simulation results that demonstrate significant gains in performance both visually and objectively (on the order of 2 dB in PSNR over forward error correction based solutions and 1.5 dB in PSNR over intrarefresh based solutions for typical scenarios) under tight latency constraints.
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paper_title: Error Concealment Techniques in Video Communication

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The problem of concealment in video communication is becoming increasingly important because of the growing interest in video delivery over unreliable channels such as wireless networks and the Internet. This paper reviews the necessity of error concealment, current error concealment techniques. These techniques are described in two categories according to temporal concealment methods and spatial errorconcealment methods.Lastly, the paper tries to analyze the direction of the development of error concealment.
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paper_title: Novel transmission method for H.264/AVC video data over wireless OFDM channels

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A novel three-dimension data interleaving method is proposed for video data transmission over wireless OFDM channels,where the three-dimensional interleaving includes interleavings in the spatial domain,frequency domain and temporal domain.The interleaving in the spatial domain is to uniformly disperse the burst bit-errors over the picture area.The frequency domain interleaving is to transmit adjacent slices over spaced sub-channels,which facilitates temporal or spatial error concealment.Temporal interleaving is to transport different slices in one OFDM sub-carrier in changed time intervals.It can provide credible reference picture for inter-frame prediction coding,and thus the error propagation over frames can be avoided,and the error concealment can be exploited too.System integrating the three-dimension data interleaving method with the multi-reference picture selection(RPS) and error concealment can efficiently improve the quality of the reconstructed video transmitted over wireless OFDM channels.Simulation results show that the proposed method can increase the PSNR of reconstructed video transmitted over OFDM wireless channels by over 4dB under different channel conditions.
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paper_title: Intelligent distributed surveillance systems: A review

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This survey describes the current state-of-the-art in the development of automated visual surveillance systems so as to provide researchers in the field with a summary of progress achieved to date and to identify areas where further research is needed. The ability to recognise objects and humans, to describe their actions and interactions from information acquired by sensors is essential for automated visual surveillance. The increasing need for intelligent visual surveillance in commercial, law enforcement and military applications makes automated visual surveillance systems one of the main current application domains in computer vision. The emphasis of this review is on discussion of the creation of intelligent distributed automated surveillance systems. The survey concludes with a discussion of possible future directions.
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paper_title: Object Trajectory-Based Activity Classification and Recognition Using Hidden Markov Models

paper_content:

Motion trajectories provide rich spatiotemporal information about an object's activity. This paper presents novel classification algorithms for recognizing object activity using object motion trajectory. In the proposed classification system, trajectories are segmented at points of change in curvature, and the subtrajectories are represented by their principal component analysis (PCA) coefficients. We first present a framework to robustly estimate the multivariate probability density function based on PCA coefficients of the subtrajectories using Gaussian mixture models (GMMs). We show that GMM-based modeling alone cannot capture the temporal relations and ordering between underlying entities. To address this issue, we use hidden Markov models (HMMs) with a data-driven design in terms of number of states and topology (e.g., left-right versus ergodic). Experiments using a database of over 5700 complex trajectories (obtained from UCI-KDD data archives and Columbia University Multimedia Group) subdivided into 85 different classes demonstrate the superiority of our proposed HMM-based scheme using PCA coefficients of subtrajectories in comparison with other techniques in the literature.
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paper_title: Utilization of texture, contrast and color homogeneity for detecting and recognizing text from video frames

paper_content:

It is possible to index and manage large video archives in a more efficient manner by detecting and recognizing text within video frames. There are some inherent properties of videotext, such as distinguishing texture, higher contrast against background, and uniform color, making it detectable. By employing these properties, it is possible to detect text regions and binarize the image for character recognition, in this paper, a complete framework for detection and recognition of videotext is presented. The results from Gabor-based texture analysis, contrast-based segmentation and color homogeneity are merged to obtain minimum number of candidate regions before binarization. The performance of the system is tested for its recognition rate for various combinations and it is observed that the results give recognition rates, reasonable for most practical purposes.
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paper_title: Object tracking: A survey

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The goal of this article is to review the state-of-the-art tracking methods, classify them into different categories, and identify new trends. Object tracking, in general, is a challenging problem. Difficulties in tracking objects can arise due to abrupt object motion, changing appearance patterns of both the object and the scene, nonrigid object structures, object-to-object and object-to-scene occlusions, and camera motion. Tracking is usually performed in the context of higher-level applications that require the location and/or shape of the object in every frame. Typically, assumptions are made to constrain the tracking problem in the context of a particular application. In this survey, we categorize the tracking methods on the basis of the object and motion representations used, provide detailed descriptions of representative methods in each category, and examine their pros and cons. Moreover, we discuss the important issues related to tracking including the use of appropriate image features, selection of motion models, and detection of objects.
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paper_title: A survey on vision-based human action recognition

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Vision-based human action recognition is the process of labeling image sequences with action labels. Robust solutions to this problem have applications in domains such as visual surveillance, video retrieval and human-computer interaction. The task is challenging due to variations in motion performance, recording settings and inter-personal differences. In this survey, we explicitly address these challenges. We provide a detailed overview of current advances in the field. Image representations and the subsequent classification process are discussed separately to focus on the novelties of recent research. Moreover, we discuss limitations of the state of the art and outline promising directions of research.
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paper_title: Segmentation of the face and hands in sign language video sequences using color and motion cues

paper_content:

We present a hand and face segmentation methodology using color and motion cues for the content-based representation of sign language video sequences. The methodology consists of three stages: skin-color segmentation; change detection; face and hand segmentation mask generation. In skin-color segmentation, a universal color-model is derived and image pixels are classified as skin or nonskin based on their Mahalanobis distance. We derive a segmentation threshold for the classifier. The aim of change detection is to localize moving objects in a video sequences. The change detection technique is based on the F test and block-based motion estimation. Finally, the results from skin-color segmentation and change detection are analyzed to segment the face and hands. The performance of the algorithm is illustrated by simulations carried out on standard test sequences.
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paper_title: Motion Context: A New Representation for Human Action Recognition

paper_content:

One of the key challenges in human action recognition from video sequences is how to model an action sufficiently. Therefore, in this paper we propose a novel motion-based representation called Motion Context (MC), which is insensitive to the scale and direction of an action, by employing image representation techniques. A MC captures the distribution of the motion words (MWs) over relative locations in a local region of the motion image (MI) around a reference point and thus summarizes the local motion information in a rich 3D MC descriptor. In this way, any human action can be represented as a 3D descriptor by summing up all the MC descriptors of this action. For action recognition, we propose 4 different recognition configurations: MW+pLSA, MW+SVM, MC+w 3-pLSA (a new direct graphical model by extending pLSA), and MC+SVM. We test our approach on two human action video datasets from KTH and Weizmann Institute of Science (WIS) and our performances are quite promising. For the KTH dataset, the proposed MC representation achieves the highest performance using the proposed w 3-pLSA. For the WIS dataset, the best performance of the proposed MC is comparable to the state of the art.
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paper_title: Action Recognition in Broadcast Tennis Video

paper_content:

Motion analysis in broadcast sports video is a challenging problem especially for player action recognition due to the low resolution of players in the frames. This paper presents a novel approach to recognize the basic player actions in broadcast tennis video where the player is about 30 pixels tall. Two research challenges, motion representation and action recognition, are addressed. A new motion descriptor, which is a group of histograms based on optical flow, is proposed for motion representation. The optical flow here is treated as spatial pattern of noisy measurement instead of precise pixel displacement. To recognize the action performed by the player, support vector machine is employed to train the classifier where the concatenation of histograms is formed as the input features. The experimental results demonstrate that our method is promising.
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paper_title: Cross-Layer combining of adaptive Modulation and coding with truncated ARQ over wireless links

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We developed a cross-layer design which combines adaptive modulation and coding at the physical layer with a truncated automatic repeat request protocol at the data link layer, in order to maximize spectral efficiency under prescribed delay and error performance constraints. We derive the achieved spectral efficiency in closed-form for transmissions over Nakagami-m block fading channels. Numerical results reveal that retransmissions at the data link layer relieve stringent error control requirements at the physical layer, and thereby enable considerable spectral efficiency gain. This gain is comparable with that offered by diversity, provided that the maximum number of transmissions per packet equals the diversity order. Diminishing returns on spectral efficiency, that result when increasing the maximum number of retransmissions, suggest that a small number of retransmissions offers a desirable delay-throughput tradeoff, in practice.
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paper_title: Error Control and Concealment for Video Communication: A Review

paper_content:

The problem of error control and concealment in video communication is becoming increasingly important because of the growing interest in video delivery over unreliable channels such as wireless networks and the Internet. This paper reviews the techniques that have been developed for error control and concealment. These techniques are described in three categories according to the roles that the encoder and decoder play in the underlying approaches. Forward error concealment includes methods that add redundancy at the source end to enhance error resilience of the coded bit streams. Error concealment by postprocessing refers to operations at the decoder to recover the damaged areas based on characteristics of image and video signals. Last, interactive error concealment covers techniques that are dependent on a dialogue between the source and destination. Both current research activities and practice in international standards are covered.
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Title: A Survey on Video Transmission Techniques

Section 1: INTRODUCTION
Description 1: This section introduces the application and importance of network video transmission, and outlines the basic processes involved in video transmission.

Section 2: Overview
Description 2: This section provides an overview of video transmission systems and discusses the importance of rate control techniques for matching the output rate of a video encoder with channel rates.

Section 3: Common RC Algorithms
Description 3: This section describes various rate-control algorithms used in video transmission, including Classical RC Model, Quadratic R-D Model, Linear Model, and Heuristic Distortion Model.

Section 4: Introduction (to Video Transmission Plans)
Description 4: This section discusses the limitations of current Internet transmission mechanisms and outlines different video transmission plans such as classification, supplementary information, environmental adaptation, and data partitioning methods.

Section 5: Common Video Transmission Control Schemes
Description 5: This section details different video transmission control schemes, categorized into RC based on the sending end, RC based on the receiving end, traffic shaping, and mixed-type RC methods.

Section 6: Target Detection
Description 6: This section introduces methods for detecting target objects in video, including background subtraction, time difference, and optical flow methods.

Section 7: Target Tracking
Description 7: This section explains techniques for tracking moving targets in video, including feature selection and common algorithms like mean shift, Kalman filtering, and particle filter.

Section 8: Video Retrieval
Description 8: This section addresses content-based video retrieval, outlining processes such as video content analysis, structure parsing, summarization, and indexing to facilitate video search and retrieval.

Section 9: Intelligent Behavioral Analysis
Description 9: This section discusses the extraction and representation of motion features, methods for behavioral analysis, and techniques such as global and local representations, state-space models, and template matching for action recognition.

Section 10: Common Error Processing of Videos
Description 10: This section covers error correction techniques in traditional video communication systems, specifically ARQ and FEC mechanisms, and highlights various error resilience and concealment methods.

Section 11: CONCLUSION
Description 11: This section provides a summary of the key points discussed in the paper, including the importance of rate control algorithms, transmission control techniques, intelligent video analysis, and error processing techniques in video transmission.