• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.2C
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• pp.186-193
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• 2009

Multi-view video is necessary to develop a new compression encoding technique for storage and transmission, because of a huge amount of data. Layered depth image is an efficient representation method of multi-view video data. This method makes a data structure that is synthesis of multi-view color and depth image. This paper proposed enhanced compression method by presentation of efficient layered depth image using real distance comparison, solution of overlap problem, and YCrCb color transformation. In experimental results, confirmed high compression performance and good reconstructed image.

• Journal of Broadcast Engineering
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• v.20 no.5
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• pp.756-769
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• 2015

In this paper, we propose a scalable coding method for high dynamic range (HDR) and standard dynamic range (SDR) videos based on Scalable High Efficiency Video Coding (SHVC). The proposed method has multi-layer coding architecture that consists of base layer for SDR videos and enhancement layer for HDR videos to support the backward compatibility with legacy codec and display devices. Also, to improve coding efficiency of enhancement layers, a global inverse tone mapping is applied to the reconstructed SDR video and the compensated frames are referred for coding of the enhancement layer. The proposed method is found to achieve BD-Rate gain of 43.0% on average (maximum 76.3%) for the enhancement layer and 15.7% on average (maximum 31%) for dual-layer against the SHM 7.0 reference software.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1996.06a
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• pp.439-443
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• 1996

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.1
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• pp.53-59
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• 2009

Multi-view video is necessary to develop a new compression encoding technique for storage and transmission, because of a huge amount of data. Layered depth image is an efficient representation method of multi-view video data. This method makes a data structure that is synthesis of multi-view color and depth image. This paper proposed enhanced compression method by presentation of efficient layered depth image using real distance comparison, solution of overlap problem, and interpolation. In experimental results, confirmed high compression performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6C
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• pp.471-479
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• 2008

In this paper, we propose a novel algorithm to automatically generate an RTP timestamp value that is required for the RTP packetization in order to transmit SVC video over various If networks such as Internet. Unlike the conventional single layer coding algorithms such as H.263, MPEG-4 and H.264, SVC generates a multi-layered single bitstream which is composed of a base layer and one or more enhancement layers in order to simultaneously provide temporal, spatial, and SNR scalability. Especially, in order to provide temporal scalability based on hierarchical B-picture prediction structure, the encoding (or transmission) and display order of pictures in SVC coding is completely decoupled. Thus, the timestamp value to be specified at the header of each RTP packet in video transmission does not increase monotonically according to the display time instant of each picture. Until now, no method for automatically generating an RTP timestamp when SVC video is loaded in a RTP packet has teen introduced. In this paper, a novel automatic RTP timestamp generation method exploiting the TID (temporal ID) field of the SVC NAL unit header is proposed to accommodate the SVC video transmission.

• Journal of Korea Multimedia Society
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• v.17 no.3
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• pp.333-341
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• 2014

Multi-view video is obtained by capturing one three-dimensional scene with many cameras at different positions. Multi-view video coding requires high computational complexity. To reduce computational complexity and maintain the image quality, an effective early termination motion estimation method is proposed in this paper. The proposed method exploiting the characteristic of motion vector distribution uses a hierarchical search strategy. This strategy method consists of multi-grid square search pattern, modified diamond search pattern, small diamond search pattern and raster search pattern. Experiment results show that the speedup improvement of the proposed method over TZ search method and FS(Full Search) method JMVC (Joint Multiview Video Coding) can be up to 1.7~4.5 times and 90 times faster respectively while maintaining similar video quality and bit rates.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.11a
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• pp.167-169
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• 2012

스케일러블 비디오 압축 기술 중 공간적 스케일러빌리티 기술에는 계층 간의 예측을 위해서 참조 계층의 영상을 향상 계층의 해상도와 동일하게 하는 영상 보간 과정이 필요하다. 본 논문에서는 HEVC (high efficiency video coding) 기반의 스케일러블 비디오 압축을 위하여 새로운 영상 보간 필터를 제안한다. 제안하는 보간 필터는 DCT (discrete cosine transform) 수식을 기반으로 설계되었으며, 하위 계층의 텍스처를 1.5 배로 보간할 때 사용된다. 제안하는 보간 필터를 적용하여 계층 간 예측을 수행할 결과, simulcast 로 부호화 한 것 대비 BD-bitrate 를 약 52.8% 감소시켰고, BD-PSNR 을 약 1.87dB 증가시켰다.

• Journal of Broadcast Engineering
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• v.19 no.2
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• pp.257-267
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• 2014

Distributed compressive video sensing (DCVS) is a low cost sampling paradigm for video coding based on the compressive sensing and the distributed video coding. In this paper, we propose using a skip-mode coding in DCVS under the assumption that in case of high temporal correlation, temporal interpolation can guarantee sufficiently good quality of nonkey frame, therefore no need to transmit measurement data in such a nonkey frame. Furthermore, we extend it to use a hierarchical structure for better temporal interpolation. Simulation results show that the proposed skip-mode coding can save the average subrate of whole video sequence while the PSNR is reduced only slightly. In addition, by using the proposed scheme, the computational complexity is also highly decreased at decoder on average by 43.75% for video sequences that have strong temporal correlation.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.793-797
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• 2008

To achieve flexible visual contents adaptation for multimedia communications, the ISO/IEC MPEG & ITU-T VCEG form the JVT to develop an SVC amendment for the H.264/AVC standard. JVT uses inter-layer prediction that can improve the rate-distortion efficiency of the enhancement layer. But inter-layer prediction causes computational complexity to be increased. In this paper, we propose a fast mode decision for inter frame coding. It makes use of the correlation between optimized prediction mode and its RD cost. Experimental results show that the proposed schemes save up to 38% of encoding time with a negligible coding loss and bit-rate increase.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.07a
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• pp.358-360
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• 2012

본 논문에서는 새로운 율모델을 기반으로한 프레임 단위 HEVC 율제어 기법을 제안한다. 기존의 비디오 압축표준과는 달리 HEVC 는 계층 구조를 지닌 쿼드트리 기반 움직임 예측 및 변환 부호화를 수행한다. 본 논문에서는 쿼드트리 계층의 깊이에 따라 신호의 통계적 특성이 매우 달라지는 것은 이용하여 라플라시안 확률 모델을 각 쿼드트리 계층에 독립적으로 이용한 새로운 율모델을 이용한 율제어 기법을 제안한다. 제안방법에서는 계층적 부호화 단위인 CU 를 계층 깊이에 따라 세 가지 카테고리로 분류하고 각 카테고리에 따라 변환 계수에 대한 라플라시안 확률 분포 함수를 율-양자화 모델을 만든다. 제안된 율모델은 특성이 매우 다른 각 CU 깊이에 따라 독립적인 라플라이안 확률 분포 함수를 이용하기 때문에 매우 정확하고 적응적인 비트율 예측이 가능하므로 보다 안정적이고 정확한 율제어가 가능하다. 실험결과는 제안된 율제어 기법이 단일 확률 분포 함수를 사용했을 경우보다 평균 0.16dB 의 PSNR 향상이 있었음을 보여주었으며 제안된 방법은 각 프레임에 대한 목표 비트에 보다 안정적으로 부호화하는 것을 보여주었다.