• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.2
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• pp.7-13
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• 2002

When a USB digital camera is used for PC video-conference applications, motion picture data need to be transferred to the PC through the USB port. Due to the mismatch between the data rates of the USB and the motion picture, data compression should be performed before the transmission from the USB. While many motion picture compression algorithms require large intermediate memory space, the JPEG algorithm does not need to store an entire frame for the compression. Instead, a relatively small buffer is required at the input of the JPEG compression engine to resolve the inconsistency between the orders of the inputted data and the consumed data. Data reordering can be easily implemented using a double buffering scheme, which still requires a considerable size of memory. In this paper, a novel memory management scheme is proposed to avoid the double buffering. The proposed memory architecture requires a small amount of memory and a simple address generation scheme, resulting in overall cost reduction.

• Spatial Information Research
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• v.19 no.1
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• pp.107-116
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• 2011

Due to development of environment of wireless Internet, location based services on the basis of spatial data have been increased such as real time traffic information as well as CNS(Car Navigation System) to provide mobile user with route guidance to the destination. However, the current application adopting the file-based system has limitation of managing and storing the huge amount of spatial data. In order to supplement this challenge, research which is capable of managing large amounts of spatial data based on embedded database system is surely demanded. For this reason, this study aims to suggest the lossless compression technique by using the hybrid approach of BytePacking and Lempel-Ziv which can be applicable in DBMS so as to save a mass spatial data efficiently. We apply the proposed compression technique to actual the Seoul and Inchcon metropolitan area and compared the existing method with suggested one using the same data through analyzing the query processing duration until the reconstruction. As a result of comparison, we have come to the conclusion that suggested technique is far more performance on spatial data demanding high location accuracy than the previous techniques.

• KIPS Transactions on Computer and Communication Systems
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• v.1 no.3
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• pp.187-192
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• 2012

This paper describes efficient H.264/AVC video scrambling methods for digital rights management. The proposed scrambling methods are to scramble level and suffix in entropy encoding and MVD in motion estimation of the H.264 video compression process. Other scrambling methods have been proposed but they degrade the compression efficiency or make it difficult to achieve real-time processing due to the large amount of computational efforts. Since the proposed scrambling methods resolve the drawbacks of other approaches, they do not cause image distortion and the original compression efficiency is maintained. We verified our scrambling methods and evaluated the performance by conducting several experiments with H.264 reference program. Finally, we implemented video player system using USB dongle in order to apply the proposed scrambling/descrambling methods to H.264 video compression.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.12 no.3
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• pp.171-190
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• 2008

With growing applications of wireless video streaming, an efficient video traffic model featuring modern high-compression techniques is more desirable than ever, because the wireless channel bandwidths are ever limited and time-varying. We propose a modeling and analysis method for video traffic by a class of stochastic processes, which we call '$GEO^Y/G/{\infty}$ input processes'. We model video traffic by $GEO^Y/G/{\infty}$ input process with gamma-distributed batch sizes Y and Weibull-like autocorrelation function. Using four real-encoded, full-length video traces including action movies, a drama, and an animation, we evaluate our modeling performance against existing model, transformed-M/G/${\infty}$ input process, which is one of most recently proposed video modeling methods in the literature. Our proposed $GEO^Y/G/{\infty}$ model is observed to consistently provide conservative performance predictions, in terms of packet loss ratio, within acceptable error at various traffic loads of interest in practical multimedia streaming systems, while the existing transformed-M/G/${\infty}$ fails. For real-time implementation of our model, we analyze G/D/1/K queueing systems with $GEO^Y/G/{\infty}$ input process to upper estimate the packet loss probabilities.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.1017-1026
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• 2012

Due to acceleration of the IT industry and the environment for a variety of media in modern society, such as real-time video images 3D-TV is a very important issue. These high-quality live video is being applied to various fields such as CCTV footage has become an important performance parameters. However, these high quality images, even vulnerable because of shortcomings secure channel or by using various security algorithms attempt to get rid of these disadvantages are underway very active. These shortcomings, this study added extra security technologies to reduce the processing speed image processing itself, but by adding security features to transmit real-time processing and security measures for improving the present.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.6
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• pp.149-157
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• 2011

In this paper, we propose a new DPCM-based transmission scheme for flight data. The amount of the flight data from LRU to MC has been increased due to the emergence and development of avionics systems and functions. It becomes a serious issue for satisfying the hard real-time processing required in the MC. In order to solve this problem, we observed the flight data produced by X-Plane simulator and discovered that the most flight data are moderately varied during flight. Based on this fact, a new data format is suggested by modifying that of ARINC-429 protocol in this paper. And the different value of the flight data is transmitted in the proposed scheme. The simulation results show that the proposed scheme achieves 20% data transfer gain compared to the ARINC-429 based transmission method.

• ETRI Journal
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• v.34 no.5
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• pp.666-673
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• 2012

Non-real-time delivery of stereoscopic video has been considered as a service scenario for 3DTV to overcome the limited bandwidth in the terrestrial digital television system. A hybrid codec combining MPEG-2 and H.264/AVC has been suggested for the compression of stereoscopic video for 3DTV. In this paper, we propose a stereoscopic video coding scheme using adaptive pre-/post-filters (APPF) to improve the quality of 3D video while retaining compatibility with legacy video coding standards. The APPF are applied adaptively to blocks of various sizes determined by the macroblock coding mode and reference frame index. Experiment results show that the proposed method achieves up to 24.86% bit rate savings relative to a hybrid codec of MPEG-2 and H.264/AVC including the inter-view prediction.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.108-111
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• 2008

In this paper, we propose an advanced hardware architecture for the CAVLC entropy encoder engine for real time Full HD video compression. Since there are 384 data coefficients which are sum of 376 AC coefficient and 8 DC coefficient per one macroblock, 384 coefficient have to be processed per one macroblock in worst case for real time processing. We propose an novel architecture which includes parallel architecture and pipeline processing, and reduction "0" in AC/DC coefficient table. To verify the proposed architecture, we develop the reference C for CAVLC and verified the designed circuit with the test vector from reference C code.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.175-181
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• 2010

In this paper, we propose a novel hardware architecture for Rate control module for real time full HD video compression. In the proposed architecture, QP is updated by using the rate control algorithm to every the macroblock line(120MB for Full HD, 20MB for CIF image). Since there are many complex arithmetic and floating point arithmetic in rate control algorithm of JM for H.264, it is impossible to process the rate control algorithm using the integer arithmetic CPU core. So we adopted floating point arithmetic unit in our architecture, and implemented the rate control algorithm using the floating unit. With this implemented hardware, the implemented hardware is verified to be operated in real time.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.12 no.1
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• pp.89-94
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• 1994

A number of the latest research projects focus on the development of real-time mapping system. Typically, these devices are used to capture land-related information in digital form from airplanes or cars. The purpose of this paper is to automatically extract the road information from the digital images obtained using the so-called "GPS-Van" which has been developed by Center for Mapping at The Ohio State University, and to propose the method for the effective storage and management of the digital data. The edges of a road can be extracted from the digital image and determined real-time 3-dimensional position by digital photogrammetry. Also, the three storage level which consists of raster data level, object-oriented data level, and vector data level in the data storage and Quadtree data structure for the effective compression and search in the data management was proposed in this paper.his paper.