Algorithm For Video Coding Research Articles

A Video Coding Algorithm Based on Improved Wavelet Coefficients Block

3D-SPIHT algorithm extends 2D-DWT to 3D-DWT and encodes the subsequent coefficients, which is a research hotspot in very low bit rate coding and data compression. This paper reorganizes the 3D-SPIHT coefficients with block structure, and puts forward the 3D-BSPIHT algorithm which can represent an insignificant block which contains four wavelet coefficients with one bit in order to improve the compression efficiency. This algorithm increases average PSNR by 0.2dB at most in comparison with 3D-SPIHT algorithm and decreases the computational complexity especially at low bit rate.

A low complexity deblocking filtering for multiview video coding

Deblocking filtering (DF) plays a major role in improving the visual quality for image and video coding. A well-designed DF scheme should achieve a good tradeoff between coding efficiency and coding complexity. The DF algorithm for multiview video coding (MVC) has adopted H.264 DF scheme to improve the video quality, which, however, leads to relatively high coding complexity. In this paper, we propose a low complexity DF algorithm in consideration of view correlation, which exploits the view correlation to skip the boundary strength (BS) computation of macroblocks (MBs) that are coded in motion skip mode. Experimental results show that the proposed algorithm can dramatically reduce DF time (35%-6%) without degrading the visual quality in comparison to the conventional algorithm.

A novel rate control algorithm for video coding based on fuzzy-PID controller

Rate control algorithms (RCAs) aim to achieve the best visual quality under the minimum bit rate and the limited buffer size. A self-parameter-tuning fuzzy-PID controller is proposed to reduce the deviation between the target buffer level and the current buffer fullness. Fuzzy logic is used to tune each parameter of the proportional-integral-derivative controller by selecting appropriate fuzzy rules through simulation in H.264/advanced video coding (AVC). To control the quality fluctuation between consecutive frames, a quality controller is adopted. The proposed RCA has been implemented in an H.264/AVC video codec, and our experimental results show that the proposed algorithm achieves smooth target bits while enabling better buffer control and visual quality.

Regional Bit Allocation and Rate Distortion Optimization for Multiview Depth Video Coding With View Synthesis Distortion Model

In this paper, we propose a view synthesis distortion model (VSDM) that establishes the relationship between depth distortion and view synthesis distortion for the regions with different characteristics: color texture area corresponding depth (CTAD) region and color smooth area corresponding depth (CSAD), respectively. With this VSDM, we propose regional bit allocation (RBA) and rate distortion optimization (RDO) algorithms for multiview depth video coding (MDVC) by allocating more bits on CTAD for rendering quality and fewer bits on CSAD for compression efficiency. Experimental results show that the proposed VSDM based RBA and RDO can improve the coding efficiency significantly for the test sequences. In addition, for the proposed overall MDVC algorithm that integrates VSDM based RBA and RDO, it achieves 9.99% and 14.51% bit rate reduction on average for the high and low bit rate, respectively. It can improve virtual view image quality 0.22 and 0.24 dB on average at the high and low bit rate, respectively, when compared with the original joint multiview video coding model. The RD performance comparisons using five different metrics also validate the effectiveness of the proposed overall algorithm. In addition, the proposed algorithms can be applied to both INTRA and INTER frames.

A Just Noticeable Distortion Based Rate Control Algorithm for Multiview Video Coding

To quantify human visual system characteristics to carry out rate controlling efficiently, this paper presents a new macroblock (MB) layer rate control algorithm for multi-view video coding (MVC) by improving quadratic rate-quantitative (R-Q) model based on the just noticeable distortion (JND) model. Firstly, the pixel-JND value of color image in multi-view video is stroked according to the related research in order to be used in the MB layer rate control. The proposed algorithm includes view layer, GOP layer, frame layer and MB layer, respectively. In the MB layer, the JND of the MB and mean absolute difference (MAD) in the quadratic R-Q model are firstly analyzed, the MAD is re-defined as perceptual MAD according to the JND with a pixel adjustment factor, and then QP of MB is computed through the re-defined quadratic R-Q model. Finally, a frequently-used image quality metric, peak signal-to-noise ratio (PSNR), is similarly re-defined as perceptual PSNR according to the JND. Experimental results show that the proposed algorithm can obtain higher image quality while precisely controls the bitrates. Moreover, the proposed algorithm not only can achieve better subjective quality, but also save the bitrates about 14.47% ~ 32.13%.

Low-Complexity Saliency Detection Algorithm for Fast Perceptual Video Coding

A low-complexity saliency detection algorithm for perceptual video coding is proposed; low-level encoding information is adopted as the characteristics of visual perception analysis. Firstly, this algorithm employs motion vector (MV) to extract temporal saliency region through fast MV noise filtering and translational MV checking procedure. Secondly, spatial saliency region is detected based on optimal prediction mode distributions in I-frame and P-frame. Then, it combines the spatiotemporal saliency detection results to define the video region of interest (VROI). The simulation results validate that the proposed algorithm can avoid a large amount of computation work in the visual perception characteristics analysis processing compared with other existing algorithms; it also has better performance in saliency detection for videos and can realize fast saliency detection. It can be used as a part of the video standard codec at medium-to-low bit-rates or combined with other algorithms in fast video coding.

Decoder-Side Motion Vector Derivation for Block-Based Video Coding

A decoder-side motion vector derivation algorithm for hybrid video coding is proposed. The algorithm is based on template matching and aims to reduce motion parameter bit-rate by re-estimating the applicable motion parameters at the decoder side. An average bit-rate savings of about 6%-8% is observed compared to the reference H.264/AVC. Decoder-side motion vector derivation was included in multiple proposals for the new High Efficiency Video Coding standard. This paper details and analyzes the algorithm and discusses its relation to other coding tools.

Multiple-layer scalable video coding technology based on MB-level data partition for wireless sensor networking

With the fast development of mobile network and communications, the number of mobile users increased amazingly. However, due to the limited bandwidth and error-prone character of the transmission channel of current wireless network, smooth real-time data transmission for mobile terminals is challenging, especially for the object which has amount of data, such as video signal. In this paper, an efficient multiple-layer scalable video coding (MLSVC) algorithm for wireless communications is proposed to avoid whole MB information loss due to the packet loss of the error-prone transmission channel. Different with the conventional scalable video coding (SVC) method, the proposed method segments the video signal in Macroblock Level (ML) during the encoding period according to the requirement of the bandwidth of the appointed wireless transmission channels to generate multiple sub-bitstreams which could be transmitted from the sender to the destination trough various channels of the wireless network. The simulation results demonstrate that our proposed ML–MLSVC algorithm can achieve excellent performance in terms of encoding processing, bandwidth occupancy, transmission time and video quality. One typical potential application for our work is that it could be employed for video signal transmission through bandwidth-limited wireless transmission channels, such as sensor and wifi network.

An Efficient Video Steganography Algorithm Based on Sub-Macroblock Partition for H.264/AVC

In this paper, a simple video steganography algorithm based on the tree structured motion compensation of the H.264 video compression standard is proposed. In the proposed method, the head data of macroblock in P/B-frames was used as a cover, the 8x8 partition modes which represent the detailed areas are selected, and information hiding is implemented by modifying the partition modes of the sub-macroblock. Experiments are designed to prove the feasibility of the proposed scheme by using different kinds of test videos. Simulation results show that, in our scheme, a high data hiding rate is obtained with a little increase on bit rate, and it also has the characteristics of high computational efficiency and imperceptibility.

A Single-Pass-Based Localized Adaptive Interpolation Filter for Video Coding

Recently, an efficient coding tool named adaptive interpolation filtering (AIF) has been proposed to hybrid video coding scheme. By introducing Wiener filter into the fractional-pixel interpolation procedure, AIF can reduce the inter-prediction error and improve coding efficiency significantly. However, the training-based Wiener filter mechanism brings AIF an inherent multi-pass encoding structure, which imposes big burdens on the encoder in terms of huge computational complexity and memory access. In this paper, we propose a single-pass-based localized adaptive interpolation filtering (SPL-AIF) algorithm for video coding, which can reduce the complexity of AIF dramatically without sacrifice of its outstanding coding performance. The proposed SPL-AIF algorithm is based on the observation that there is a high correlation among optimal interpolation filters of consecutive frames, and different regions in a frame often possess different statistical characteristics. Accordingly, the proposed algorithm can be designed including two major parts. First, a competitive filter set which includes the optimal interpolation filters of several previous frames as well as the fixed H.264/AVC interpolation filters is built up for the coding of the current frame. Then a rate-distortion optimization criterion is used to select the best one at macroblock (MB) level. In order to reduce overhead, a predictive coding method is used to compress the filter signaling flag for each MB. Experimental results show that, by using the proposed algorithm, the encoding complexity can be reduced significantly while the average coding gain in Bjontegaard distortion bit-rate reduction can be improved about 1% compared with the multi-pass AIF. The proposed method has been adopted into the Video Coding Expert Group Key Technology Area software.

The Improvement of UMHexagonS Algorithm in AVS Video Coding

To reduce the complexity of AVS pixel motion vector search, this paper proposes a improved AVS pixel motion estimation UMHexagonS algorithm. The algorithm adds the improve of advanced new array and adaptive adjustment search template. To the video sequence of different motion feature, compare with UMHexagonS algorithm, in the case of mean PSNR descend less than 0.01dB and bitrate only mean increase 0.54％, the time of pixel motion estimation is reduced by 8.72％～20.25％ and the calculated amount of pixel motion estimation is also reduced.

The Improvement of UMHexagonS Algorithm in AVS Video Coding

To reduce the complexity of AVS pixel motion vector search, this paper proposes a improved AVS pixel motion estimation UMHexagonS algorithm. The algorithm adds the improve of advanced new array and adaptive adjustment search template. To the video sequence of different motion feature, compare with UMHexagonS algorithm, in the case of mean PSNR descend less than 0.01dB and bitrate only mean increase 0.54％, the time of pixel motion estimation is reduced by 8.72％～20.25％ and the calculated amount of pixel motion estimation is also reduced.

A Fast and Adaptive Search Algorithm Based on Rood Pattern and Gradient Descent

Abstract In order to achieve the real-time property for video coding, a fast and adaptive algorithm based on starting search point prediction and early-termination strategy is proposed. It analyzes center-bias property and spatial correlation property of motion vector field, and utilizes the respective characteristics of block based gradient descent search (BBGDS) and adaptive rood pattern search (ARPS) algorithm. The proposed algorithm adaptively chooses different searching strategies according to the type of the image, makes full use of the cross image motion vector distribution characteristics and optimizes the traditional ARPS algorithm. The experimental results show that the proposed algorithm is about 2.3∼9.2 times faster than Diamond Search (DS), 1.2∼4.0 times than ARPS. The algorithm can meet the real-time demand without reducing the image quality.

A one-pass estimation algorithm for real-time video coding

A one-pass estimation algorithm for real-time video coding

Efficient Motion Estimation Algorithms for Video Coding

This work proposes an efficient motion estimation algorithm for video coding. The proposed method calculates the partial distortion by replacing a certain number pixels of each partial sub-macroblock. In addition to increase the probability of the rejection of unsuitable motion vectors without additional computations, the proposed approach reduce computational complexity significantly and obtains better objective quality than conventional motion estimation algorithms.

Adaptive Motion Search Range Prediction for Video Encoding

An adaptive motion search range (SR) prediction algorithm for video coding is proposed in this letter. To determine a proper SR size for motion vectors (MVs) is important to video encoding, since a good choice helps reduce the memory access bandwidth while maintaining the rate-distortion coding performance. To achieve this objective, we first obtain a motion vector predictor (MVP) for a target block based on MVs of its spatially and temporally neighboring blocks, which form a MV prediction set. Then, we relate the variance of the MV prediction set to the SR. That is, a larger variance implies lower accuracy of the MVP and, thus, a larger SR. Finally, we derive a probability model for the motion vector prediction difference, the difference between the optimal MV and the MVP, to quantify the probability for a chosen SR to contain the optimal MV. The superior performance of the proposed SR selection algorithm is demonstrated by experimental results.

Efficient Bit Allocation and Rate Control Algorithms for Hierarchical Video Coding

Hierarchical structure is a useful tool for providing the necessary scalability in adapting to the variety of channel environments. For schemes involving hierarchical picture structures, bit allocation, and rate control algorithms are vital components for improving video codec performance. Since conventional bit allocation schemes do not efficiently consider the hierarchical structure characteristics, it is difficult to optimize the video quality at an arbitrary bitrate. Similarly, conventional quantization parameter decision methods are not appropriate for controlling the bitrate generated by a codec using a hierarchical encoding structure. In this paper, we propose an effective bit allocation scheme that assigns the target number of bits to pictures or macroblocks (MBs) and improves the overall quality of images encoded by a hierarchical-based encoder. A rate control scheme is also proposed to ensure that the generated bitrate is equal to the assigned target bitrate. From the simulation results, the proposed schemes outperformed conventional methods from a rate-distortion perspective, by efficiently controlling the bitrate of the MB unit. The algorithms regulated the generated bits to achieve the target bits by using the proposed linear R-Q model.

Fast mode decision algorithm for spatial scalable video coding

Multimedia applications are ubiquitous in daily life. To satisfy multiple requests equipped with different devices and bandwidths, scalable video coding has been developed. However, it is difficult to realise spatial and quality scalabilities in practice owing to the increased coding complexity brought by inter-layer prediction. A novel fast mode decision algorithm for spatial scalable video coding is proposed in which macroblock modes in the base layer and the enhancement layer are predicted from each other. The experimental results show that the proposed algorithm provides up to 74% of time saving with ignorable quality degradation and acceptable bit rate increase.

Quality of experience in multicast hybrid networks: avoiding bandwidth wasting with a double-stage FEC Scheme

Quality of experience is becoming an important parameter for estimating the end user perceived video quality. Video coding algorithms are currently increasing the compression performances by exploiting the temporal and spatial correlations of multimedia information. Such a trend is self-defeating in hybrid networks, due to the frequent channel impairments experienced. Here, the authors present a double-stage forward error correction (FEC) scheme to reduce the channel impairments that a multimedia communication undergoes when broadcasting a video stream through an hybrid infrastructure constituted by satellite and terrestrial wireless links. The authors present a detailed statistical description of the terrestrial wireless channel and exploit it to design the parameters for tuning the algorithm. Simulations results show that this approach not only performs better than the error recovery techniques currently used in the literature, but it also experiences a significant reduction in the bandwidth overhead.

Fast macroblock mode selection algorithm for multiview depth video coding

Huge computational complexity of multiview video plus depth (MVD) coding is an obstacle for putting MVD into applications. A fast macroblock mode selection algorithm is proposed to reduce the computational complexity of multiview depth video coding. The proposed algorithm, implementing on a joint coding scheme, combines an effective prediction mechanism and an object boundary discriminating method. The prediction mechanism which is designed based on the macroblock mode similarities reduces the number of macroblock mode candidates in depth video coding. The object boundary discriminating method extracts the regions, which are with discontinuous depth values and important for virtual view rendering, by using macroblock deviation factor. Experimental results show that the proposed algorithm can significantly promote the coding speed of depth video by 2.00-3.40 times, while maintaining high rate distortion (RD) performance in comparison with the full search algorithm.