• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.1019-1024
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• 2005

MPEG-2 achieves high compression radio, by exploiting the temporal and spatial correlations in real image sequence, using the motion compensated prediction and the transform coding, respectively. However, as the image sequence is more highly compressed, the encoded bitstream becomes more vulnerable to transmission error over the noisy channels. Furthermore, er개rs in the headers are fatal to decoding processes, because the header parameters in the video coding standard include a lot of important information connected to the syntax elements, fables, and decoding process. In this paper, we propose a new error resilience method using LSB coding for header parameters in MPEG-2 coded video transmissions. The experimental results for football and susie video sequence demonstrate that the proposed error resilience method for header parameters in MPEG-2 bitstream has good performance.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.1
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• pp.132-140
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• 2011

Ultra-High Definition Television (U-HDTV) is a promising candidate for the next generation television. Since the U-HDTV video signal requires a huge amount of data, parallel implementation of the U-HDTV compression system is highly demanding. In the conventional parallel video codec, a video is divided into sub-sequences and the sub-sequences are independently encoded. In this paper, for efficient parallel processing, we propose a pipelined encoding structure which exploits cross-correlation among the sub-sequences. The experimental results demonstrate that the proposed technique improves the coding efficiency and provides the sub-sequences of the balanced visual quality.

• Convergence Security Journal
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• v.11 no.3
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• pp.47-54
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• 2011

To protect SVC(Scalable Video Coding) media, the encryption mechanism need to consider two fundamental issues; First, What is to be encrypted? Second, When encryption is performed with respect to compression? In this paper, we analyze the several encryption approaches with regard to the above issue. And we propose hybrid-based protection mechanism. This mechanism ensures the media scalability, layered access control and reuse protected content. In this experiment the proposed mechanism generates under 3% security overhead against standard scalable video coding.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.6
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• pp.3165-3181
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• 2019

Spherical videos, which are also called 360-degree videos, have become increasingly popular due to the rapid development of virtual reality technology. However, the large amount of data in such videos is a huge challenge for existing transmission system. To use the existing encode framework, it should be converted into a 2D image plane by using a specific projection format, e.g. the equi-rectangular projection (ERP) format. The existing high-efficiency video coding standard (HEVC) can effectively compress video content, but its enormous computational complexity makes the time spent on compressing high-frame-rate and high-resolution 360-degree videos disproportionate to the benefits of compression. Focusing on the ERP format characteristics of 360-degree videos, this work develops a fast decision algorithm for predicting the coding unit depth interval and adaptive mode decision for intra prediction mode. The algorithm makes full use of the video characteristics of the ERP format by dealing with pole and equatorial areas separately. It sets different reference blocks and determination conditions according to the degree of stretching, which can reduce the coding time while ensuring the quality. Compared with the original reference software HM-16.16, the proposed algorithm can reduce time consumption by 39.3% in the all-intra configuration, and the BD-rate increases by only 0.84%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1472-1480
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• 2016

When disasters such as earthquake, flood, typhoon, fire and terrorism are occurred a video management system is required which can shoot video on the disaster site, and send it to a server located in the command center that can grasp at a glance the site conditions. In this paper, to know the performance elements information needed to construct the video management system. we presented a method of configuring an ad hoc network based on Wi-Fi direct communication. And we also evaluated the performance through built of environment for the video management system. The evaluated performance test items are 'packet flow tests according to the video compression ratios and the image sizes', 'packet flow tests according to the distance and traffic tests', 'packet flow tests according to whether LOS or not', and 'performance test of scenarios'.

• Journal of Korea Multimedia Society
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• v.9 no.7
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• pp.864-871
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• 2006

With the advancement of the digital broadcasting and popularity of Internet, there is an increasing demand for digital data. Recently, several studies have been made on the digital watermarking for copyright protection of digital data. We propose a blind video watermarking using minimum modification of motion vectors. Conventional methods based on motion vectors do watermarking using modification of motion vectors. However, change of motion vectors results in the degradation of video quality. Thus, our proposed algorithm minimizes modification of the original motion vectors to avoid degradation of video quality using simple embedded conditions. Besides, our scheme guarantees the amount of embedded watermark data using the adaptive threshold considering the human visual characteristic. In addition, this is compatible with current video compression standards without changing the bitstream. Experimental result shows that the proposed scheme obtains better video quality than other previous algorithms by about $0.5{\sim}1.0\;dB$.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.6
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• pp.71-80
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• 2011

According to rapid development of communication and video compression technology, the video contents are easily disseminated into various areas. In order to prevent illegal distribution of video contents, the necessity of video contents protection technology is increased. In this paper, we propose the video encryption and decryption algorithm based on logistic map and design the prototype system in real-time embedded environment. The sender system with encryption capability is implemented on DM642 EVM target board and the receiver system with decryption capability is implemented in satellite D-STB. Experimental results show that the time change ratio of encoding process on target board are less than 0.97% and the time change ratio of the decoding process on D-STB is less than 1.75%. So, we verify that the proposed encryption/decryption system can be used in real time application.

• Journal of Korea Multimedia Society
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• v.15 no.9
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• pp.1093-1101
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• 2012

Multi-view video is obtained by capturing one three-dimensional scene with many cameras at different positions. Multi-view video coding exploits inter-view correlations among pictures of neighboring views and temporal correlations among pictures of the same view. Multi-view video coding which uses many cameras requires a method to reduce the computational complexity. In this paper, we proposed an efficient prediction structure to improve performance of multi-view video coding. The proposed prediction structure exploits an average distance between the current picture and its reference pictures. The proposed prediction structure divides every GOP into several small groups to decide the maximum index of hierarchical B layer and the number of pictures of each B layer. Experimental results show that the proposed prediction structure shows good performance in image quality and bit-rates. When compared to the performance of hierarchical B pictures of Fraunhofer-HHI, the proposed prediction structure achieved 0.07~0.13 (dB) of PSNR gain and was down by 6.5(Kbps) in bitrate.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.4
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• pp.493-498
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• 2009

Bluetooth is a popular wireless data transmission method with low power consumption, but it has low data transmission rate. Thus, although many video stream players of a local or network file exist, there have been few players of video stream transmitted via Bluetooth. MPEG-4 AVC/H.264 codec is one of video codecs available with best compression rates for a certain quality, so a H.264 encoder seems to be adequate for video stream to be transmitted via Bluetooth. In this paper, we present a DirectShow filter based player of video stream encoded by H.264 codec, which is transmitted via Bluetooth. Details on the design and implementation of this program are described. Experimental results are shown to demonstrate the validity of the implemented program using various video samples.

• Journal of Broadcast Engineering
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• v.18 no.6
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• pp.816-822
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• 2013

The latest video coding standard HEVC was developed by the joint work of JCT-VC(Joint Collaborative Team on Video Coding) from ITU-T VCEG and ISO/IEC MPEG. The HEVC standard reduces the BD-Bitrate of about 50% compared with the H.264/AVC standard. However, using the various methods for obtaining the coding gains has increased complexity problems. The proposed method reduces the complexity of HEVC by using both CPU parallel processing and GPU-accelerated processing. The experiment result for UHD($3840{\times}2144$) video sequences achieves 15fps encoding/decoding performance by applying the proposed method. Sooner or later, we expect that the H/W speedup of data transfer rates between CPU and GPU will result in reducing the encoding/decoding times much more.