• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.7
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• pp.2449-2463
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• 2014

Hierarchical B-frame coding was introduced into H.264/SVC to provide temporal scalability and improve coding performance. A content analysis-based adaptive group of picture structure (AGS) can further improve the coding efficiency, but damages the inter-frame correlation and temporal scalability of hierarchical B-frame to different degrees. In this paper, we propose a group of pictures (GOP) adaptation coding method based on the positions of video cuts. First, the cut positions are accurately detected by the combination of motion coherence (MC) and mutual information (MI); then the GOP is adaptively and proportionately set by the analysis of MC in one scene. In addition, we propose a binary tree algorithm to achieve the temporal scalability of any size of GOP. The results for test sequences and real videos show that the proposed method reduces the bit rate by up to about 15%, achieves a performance gain of about 0.28-1.67 dB over a fixed GOP, and has the advantages of better transmission resilience and video summaries.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.294-297
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• 2009

Multi-view video consists of a set of multiple video sequences from multiple viewpoints or view directions in the same scene. It contains extremely a large amount of data and some extra information to be stored or transmitted to the user. This paper presents inter-view correlations among video objects and the background to reduce the prediction complexity while achieving a high coding efficiency in multi-view video coding. Our proposed algorism is based on object-based segmentation scheme that utilizes video object information obtained from the coded base view. This set of data help us to predict disparity vectors and motion vectors in enhancement views by employing object registration, which leads to high compression and low-complexity coding scheme for enhancement views. An experimental results show that the superiority can provide an improvement of PSNR gain 2.5.3 dB compared to the simulcast.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.137-141
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• 1997

In this study, in order to improve visualization and enhance the ability of the surgeon to perform delicate endoscopic surgery, three dimensional endoscopic system is designed. These 3D systems have our features of stereoendoscopic image processing: real time image capture and retrieve; presentation of left and right image on a single monitor; separable processing of the left and right eye images; coding of the 3D endoscopic video. For 3D endoscopic video coding, three approaches are presented based on interlaced picture structure, side-field format structure, and simulcast technique. Experimental results and performances comparisons are presented and analyzed or these approaches. Digital video coding techniques are presented or 3D endoscopic video sequences by means of an MPEG-2 video coding.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.11C
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• pp.1123-1129
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• 2003

In the H.264 video coding standard, the information for the macroblock is encoded by the independent syntax elements, called RUN and MB_type. Through the experimental observation for various test sequences, it is shown that the performance of the video coding is improved by using the combined RUN and MB_type as an entity. Based on this fact, we propose an unified new syntax element composed of the RUN and MB_type in order to improve the compression ratio of H.264 video coding. In the proposed syntax element, an EOF(End-Of-Frame) symbol indicating the end of picture is used for enhancing the performance of video coding. The simulation result shows that the proposed method outperforms maximally 15 % to the conventional method for the bitrate of the macroblock.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9C
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• pp.1244-1251
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• 2004

In this paper, we propose an efficient dynamic coding scheme by using multiple code words in H.264/A VC entropy coding. The exponential Golomb (Exp-Golomb) code words used in H 264/A VC do not reflect enough the symbol distributions of the combined syntax element in [7] due to their static probability distribution characteristics However, the multiple codewords in this paper have different statistical characteristics. we propose a dynamic coding scheme by using selectively among multiple codewords to encode the combined syntax clement according to given image sequences. Simulation results show that our proposed scheme outperforms the existing [7] me in compression efficiency without loss of quality.

• Journal of IKEEE
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• v.21 no.3
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• pp.280-283
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• 2017

HEVC (high efficiency video coding) exploits CABAC (context-based adaptive binary arithmetic coding) for entropy coding, where a context model estimates the probability for each syntax element. In this paper, a context modeler was designed and implemented for CABAC decoding. lookup table was used to reduce computation and to increase speed. 12 simulations for HEVC standard test sequences and encoder configurations were performed, and the context modeler was verified to perform correction operations. The designed context modeler was synthesized in 0.18um technology. Maximum frequency, maximum throughput, and gate count are 200 MHz, 200 Mbin/s, and 29,268 gates, respectively.

• Journal of Broadcast Engineering
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• v.16 no.5
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• pp.793-796
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• 2011

H.264/AVC compresses video data by applying DCT transform, quantization and entropy coding processes to the residual signal obtained by inter/intra prediction. This paper proposes a method enhancing an existing DC offset adjustment technology which uses information of neighboring blocks to reduce residual information for improving coding efficiency. DC offset information is not sent over bitstreams, but calculated in the same way both in the decoder and in the encoder. Experimental results show that the proposed method enhances coding efficiency by 0.25% in average BD-Rate compared to H.264/AVC and gives better or worse coding efficiency compared to the existing DC offset method depending on video sequences with coding efficiency degradation by 0.09% in average BD-Rate. This experimental results also show that further coding efficiency improvement is possible by applying the proposed method adaptively to slice or macroblock coding units.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8C
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• pp.720-728
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• 2007

For the improvement of coding efficiency, the H.264/AVC video coding standard employs new coding tools compared with existing coding standards. However, due to these new coding tools, the complexity of H.2641AVC encoder is greatly increased. Specially, Inter/Intra mode decision method of H.264/AVC using RDO(rate-distortion optimization) technique is one of the most complex parts in H.264/AVC. In this paper, we focus on the complexity reduction in macroblock mode decision considering coding efficiency. From the simulation results, the proposed algorithm reduce the encoding time by maximum 80% of total, and reduce the bitrate of the overall sequences by $8{\sim}10%$ on the average compared with existing coding methods.

• Journal of Broadcast Engineering
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• v.13 no.1
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• pp.137-151
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• 2008

H.264/AVC is showed high coding efficiency more than previous video coding standard by using new coding tools. Specially, Variable block-based motion estimation and Rate-Distortion Optimization are very important coding tools in H.264/AVC. These coding tools have high coding efficiency, however the encoder complexity greatly increase due to these coding tools. In this paper, we propose early SKIP mode decision and selective inter/intra mode decision to reduce the computational complexity. Simulation results show that the proposed method could reduce encoding time of the overall sequences by 30% on average than JM 10.2 without noticeable degradation of coding efficiency. Besides, the proposed method runs over twice as fast as the previous proposed Fast Coding Mode Selection method (FCMS)[5].

• Journal of Broadcast Engineering
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• v.18 no.6
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• pp.835-849
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• 2013

Joint Collaborative Team on Video Coding (JCT-VC), which have founded ISO/IEC MPEG and ITU-T VCEG, has standardized High Efficiency Video Coding (HEVC). Standardization of HEVC has started with purpose of twice or more coding performance compared to H.264/AVC. However, flexible and hierarchical coding block and recursive coding structure are problems to overcome of HEVC standard. Many fast encoding algorithms for reducing computational complexity of HEVC encoder have been proposed. However, it is hard to implement a real-time HEVC encoder only with those fast encoding algorithms. In this paper, for implementation of software-based real-time HEVC encoder, data-level parallelism using SIMD instructions and CPU/GPU multi-threading methods are proposed. And we also proposed appropriate operations and functional modules to apply the proposed methods on HM 10.0 software. Evaluation of the proposed methods implemented on HM 10.0 software showed 20-30fps for $832{\times}480$ sequences and 5-10fps for $1920{\times}1080$ sequences, respectively.