This study presents a fast intra-prediction algorithm for a high-profile H.264 encoder. First, a pre-decision algorithm is proposed to reject the impossible block size based on image variance. Then a fast 4x4 block pr...
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This study presents a fast intra-prediction algorithm for a high-profile H.264 encoder. First, a pre-decision algorithm is proposed to reject the impossible block size based on image variance. Then a fast 4x4 block prediction algorithm is proposed to select four possible modes from nine predicted modes based on the edge-filtering detection. With a hierarchical approach, the 8x8 block prediction is based on the result of the chosen 4x4 block mode. This approach selects only one to five modes of H.264 coding from nine prediction modes. Following the prediction of the 16x16 luminance block and 8x8 chrominance block is mapped by the result of the 8x8 luminance block by checking only one to two modes. The pre-decision algorithm, the fast 4x4, 8x8 and 16x16 block prediction algorithms can be combined to improve the coding speed. Simulations demonstrate that the proposed algorithm can save about 70% coding time at most for intra-frame coding in the H.264 system while increasing only about 1% bit-rate with a negligible peak signal-to-noise ratio drop.
H.264/AVC FRExt (Fidelity Range Extensions) and Motion JPEG 2000 are the current respective inter-frame and intra-frame coding standards for high resolution (HR) (e.g., 4096 x 2160) visual signals. It is commonly beli...
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H.264/AVC FRExt (Fidelity Range Extensions) and Motion JPEG 2000 are the current respective inter-frame and intra-frame coding standards for high resolution (HR) (e.g., 4096 x 2160) visual signals. It is commonly believed that an inter-frame method could achieve higher coding efficiency compared with an intra-frame one, due to the exploitation of video temporal redundancy. However, Motion JPEG 2000 has been selected as the digital cinema compression standard, and some existing work has demonstrated that JPEG 2000 is more suitable at HR situations. In this paper, we compare the rate-distortion (R-D) performance of these two different schemes and give more insight from both theoretical and experimental point of view. We derive an entropy-based R-D model to analyze the test results and the impact of residual entropy and quantization for inter-framecoding. Several extensions are introduced into H.264/AVC FRExt for HR video content for better performance. Experimental results show that these extensions lead to significantly higher coding efficiency and make our extended version more suitable for HR video coding (C) 2011 Elsevier inc. All rights reserved.
In the intra-frame coding of H.264/AVC, information hiding can be implemented by modulating the prediction modes of 4 x 4 luminance blocks. Because such kind of methods has characteristics of high speed, good concealm...
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In the intra-frame coding of H.264/AVC, information hiding can be implemented by modulating the prediction modes of 4 x 4 luminance blocks. Because such kind of methods has characteristics of high speed, good concealment, and so on, it is very suitable to build the covert communication system based on video communications and brings a great public security threat. Therefore, it is important to study its steganalysis method. In this paper, we first analyzed the changes of remarkable characteristics in intra-frame coding caused by modulating intra-prediction modes for information hiding, and found that the inherent correlation among the prediction modes in different 4 x 4 luminance blocks belonging to an intra-frame coding macroblock was changed. According to several different positional relationships of the adjacent 4 x 4 blocks in spatial domain, we designed statistical models corresponding to the prediction mode correlation to make quantitative extraction of these correlation characteristics. An information hiding detector was constructed based on the support vector machine. Based on the constructed detector, the experimental results show that the mean of the detection accuracy, recall ratio, and precision ratio are all excellent for different test video sequences.
Global security is a matter of critical concern that requires adoption of advanced monitoring technologies. Efficient surveillance systems comprise extensive camera networks across large areas to ensure comprehensive ...
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Global security is a matter of critical concern that requires adoption of advanced monitoring technologies. Efficient surveillance systems comprise extensive camera networks across large areas to ensure comprehensive coverage. However, the large volume of data generated by these networks poses challenges for traditional storage and computational resources. This paper presents an innovative video compression technique that focuses on optimizing data management in visual surveillance systems by selectively masking temporal information between frames. This technique introduces a specially designed adaptive masking filter, which hides the undetectable motion in video sequences and enhances video compression. The introduced masking technique uses an adaptive masking parameter 'q' to improve frame prediction or to compensate for the masked temporal activity during decoding and achieves over 30% bit-rate reduction compared to the standard video encoding schemes, such as H.264/AVC. Moreover, the introduced technique also reduces the computational demands while keeping the quality of the output. This can be evidenced by a Peak Signal to Noise Ratio (PSNR) of 33.67 dB and a Structural Similarity Index (SSIM) of 92.7% in a traffic video sequence. The proposed technique holds the potential to be used in efficient IoT-driven video surveillance systems to process video frames efficiently without compromising quality.
A multiple camera surveillance system is typical example of a Distributed Video (DV) system with many-to-one topology which demands the use of new paradigm with multiple encoders, installed at number of locations and ...
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ISBN:
(纸本)9781424416875
A multiple camera surveillance system is typical example of a Distributed Video (DV) system with many-to-one topology which demands the use of new paradigm with multiple encoders, installed at number of locations and very few decoders in a control room. This paradigm open-up new frontiers for the research community in designing low cost encoders even at the cost of expensive decoders. A solution to this problem based on information theory finding of 70s, by Slepian and Wolf [3], for lossless encoding, and followed by the work of Wyner and Ziv [5], for lossy encoding. In the last few years there has been significant research activity in the design and implementation of video codec based on these findings. Our research work is also part of that effort. In this paper we will present a modified Wyner-Ziv codec, that take advantage of slow motion activity, which is typically of surveillance data. GOP is selected dynamically by accessing motion activity and also puncturing bit rate varies adaptively. Also the proposed architecture takes advantage of intra-frame coding for both key frame and Wyner-Ziv frames.
Line-based coding has shown its potential in improving the coding efficiency of intra-frame/ image coding due to its flexibility in prediction. In our previous work we proposed an efficient line-based image coding met...
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ISBN:
(纸本)9780819482341
Line-based coding has shown its potential in improving the coding efficiency of intra-frame/ image coding due to its flexibility in prediction. In our previous work we proposed an efficient line-based image coding method (LIC) by adaptive line-by-line prediction (ALP) and adaptive residue coding. In this paper we further improve this line-based coding scheme by exploiting long-distance correlations in prediction. Line-by-line template matching (LTM) is introduced to perform the long-distance prediction. Experiments in the KTA software show that the LTM scheme can effectively improve the performance of LIC at low bitrates and also brings some improvement at high bitrates. Up to 1db gain is achieved compared to previous LIC and 1.5db compared to KTA on images with regular patterns or strong edges. Up to 20% rate reduction over KTA is also achieved on some standard video sequences with different resolutions.
To achieve high visual quality of intra-frame coding in order to minimize the visual quality degradation caused by color loss, the authors previously presented an RGB-domain inter-color compensation algorithm using st...
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ISBN:
(纸本)9781424456536
To achieve high visual quality of intra-frame coding in order to minimize the visual quality degradation caused by color loss, the authors previously presented an RGB-domain inter-color compensation algorithm using strong correlation between RGB color components. Based on that inter-color compensation algorithm, this paper presents a 1080p 60Hz CODEC system architecture designed to process a bit-rate of up to approximately 100Mbps in real time. Both the encoding and decoding processes are pipelined on a macroblock level. Since syntax processing is a bottleneck to supporting speeds of up to 100Mbps, a high performance context-adaptive variable length coding architecture exploiting the look-ahead technique is included in the proposed design. The final chip implementation can achieve real-time encoding and decoding of 1080p 60Hz videos with reasonable hardware cost and operating clock frequency.
Due to the newly adopted Quad Tree with Nested Multi-Type Tree (QTMT) partitioning scheme in Versatile Video coding (VVC), multiple partitioning combinations can lead to the same coding Unit (CU) structure. In other w...
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ISBN:
(纸本)9781665432870
Due to the newly adopted Quad Tree with Nested Multi-Type Tree (QTMT) partitioning scheme in Versatile Video coding (VVC), multiple partitioning combinations can lead to the same coding Unit (CU) structure. In other words, a CU may be encoded more than once. Based on this feature, a history-based complexity reduction strategy is proposed to accelerate VVC intra-frame coding with extremely low coding losses. Firstly, analyses of the relationship between the 1st round CUs (encoded at the first time) and the following rounds CUs (encountered again and already analyzed in previous partitioning attempts) are provided. Correspondingly, some unnecessary partitioning types are identified and early terminated. Secondly, a hierarchical pruning algorithm is designed, where thresholds are adjusted adaptively in the 1st round and used for pruning in the following rounds. To our knowledge, it is the first attempt to apply this history-based feature to accelerate partitioning for VVC intra-frame coding. Results show that these strategies can achieve 20% encoding time saving (TS) with only 0.18% BDBR increase. In addition, there is a huge potential for High-Resolution videos (21% TS with only 0.1% BDBR increase for 4K sequences). Compared to other works, our method achieves a considerably high TS/BDBR ratio, which indicates a better tradeoff between coding efficiency and complexity.
In the paper is presented one new approach for efficient presentation of video sign language interpretations, used in training of hearing impaired people. The idea is based on the use of contour image sequences instea...
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ISBN:
(纸本)9788022728560
In the paper is presented one new approach for efficient presentation of video sign language interpretations, used in training of hearing impaired people. The idea is based on the use of contour image sequences instead of the original color ones. The aim is to achieve efficient compression, which to offer easier access for distance learning applications or mobile communications. The contours extraction is based on image filtration and background equalization, followed by image segmentation and lossless intra-frame compression of the consecutive TV frames of the video interpretations. In result, the understandability of the sign language interpretations is retained. The high compression ratio obtained ensures easier accessibility for the presented information. The comparison with other similar methods proved the efficiency of the new approach. http://***/stamp/***?tp=&arnumber=4604396
This paper proposes the directional filtering transform (dFT, in order to distinguish from the common usage on DFT) to better exploit intra-frame correlation in H.264 intra-frame coding. It consists of a directional f...
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ISBN:
(纸本)9781424442904
This paper proposes the directional filtering transform (dFT, in order to distinguish from the common usage on DFT) to better exploit intra-frame correlation in H.264 intra-frame coding. It consists of a directional filtering and an optional DCT transform. In the proposed directional filtering, there are two different approaches. One is the uni-directional filtering (UDF) that is similar to H.264 directional intra prediction. In this approach, only samples from neighboring blocks can be used in prediction. Another is bidirectional filtering (BDF) that exploits the correlations among samples from not only neighboring blocks but also the current block. The prediction structure in this approach is hierarchical multi-layer. In this paper, we present mathematical analyses on UDF and BDF and show the advantage to combine them together. The proposed dFT is integrated into H.264 intra-frame coding too. The preliminary experimental results in H.264 demonstrate its superiority.
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