• Journal of Broadcast Engineering
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• v.25 no.3
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• pp.313-324
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• 2020

In this paper, we propose a motion vector prediction method that increases the coding efficiency at the boundary of an image by utilizing the 360 video characteristic. In the current VVC method, the location of a neighbor block is excluded from the candidate list for inter prediction in case that it is out of boundary. This can reduce coding efficiency as well as subject quality. To solve this problem, we construct new candidates adding the location of the neighbor block at the boundary of the picture from already decoded information based on the projection method for 360 video coding. To evaluate the performance of the proposed method, we compare with VTM6.0 and 360Lib9.1 under Random Access condition of JVET-360 CTC. As a result, the coding performance shows a BD-rate reduction of 0.02% on average in luma component and 0.05%, 0.06% on average in chroma components respectively, without additional computational complexity. The coding performance at the picture boundary shows a BD-rate reduction of 0.29% on average in luma component and 0.45%, 0.43% on average in chroma components, respectively. Furthermore, we perform subjective quality test with the DSCQS method and obtain MOS values. The MOS value is improved by 0.03 value, and we calculate BD-MOS using MOS value and bit-rate. As a result, the proposed method improved performance by up to 8.78% and 5.18% on average.

• Korean Journal of Digital Imaging in Medicine
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• v.10 no.1
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• pp.13-19
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• 2008

Purpose : In sponge quality of the material in digital radiography environment coating because do position blocks two that do not become coating done positioning blocks two that do not become coating done positioning block and sponge quality of the material to testing bench image artifact's difference compare. Method of study : In digital radiography environment positioning block of different two products same sunshine or effect that image and positioning block artifact gents in image analyze. the target used positioning block 2 when examine hand, rib and examination condition did each differently according to used positioning block. reflex compared picture that do image and verify that examine first time. Result : 1. In sponge quality of the material coating in done product artifact appear. Did not appear in product that do not become coating. 2. Can know coating's existence, that artifact according to radish happens. 3. Quality of the material coating's existence, there was difference of slippage according to radish Conclusion : Quality of the material coating phenomenon that done positioning block thus, it may have to be considered that use after estimate degree that get in image.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.2
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• pp.92-100
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• 2020

Currently, the demand for underwater or underwater photography is growing very fast. Its coverage of underwater shooting for broadcasting, leisure and sports, and military and operational use is also growing rapidly. Among them, we specifically select the best camera to be used in underwater drones to photograph and inspect marine life attached to the ship's hull. To compare three cameras performance, they are compared and evaluated using objective and subjective criteria in special circumstances such as underwater shooting. This study checks whether performance criteria, such as resolution of a camera, meet objective and subjective standards in the unusual situation of underwater shooting. And it shows that in addition to the filter that calibrates the image, proper camera selection is important for providing good picture quality. Even after this study, research using more diverse cameras could provide an appropriate standard for comparison of underwater camera quality.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.8
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• pp.1069-1082
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• 1993

The International Organization for Standardization(ISO) has undertaken an effort to develop a standard for video and associated audio on digital storage media. This effort is known by the name of the expert group that started if : MPEG-Moving Picture Experts Group Is currently part of the ISO-I EC/J TC1/SC2/WG11. The promise of MPEG-2 is that a video signal and its associated audio can be compressed to a bit rate of about 10 Mbits/s with an acceptable quality. In this paper, the implementation of a video compression simulator based on MPEG-2 Video Test Model 2(TM2) is described and analyzed according to the simulation results. The implemented simulator is also applied to code HDTV sequences at the several bit rates. Some computer simulation results using the MPEG and the HDTV test sequences are given. In addition, some techniques which can improve the coding efficiency of the implemented video compression simulator are also suggested.

• Korean Journal of Remote Sensing
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• v.27 no.5
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• pp.573-586
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• 2011

The MTF(modulation transfer function) is one of parameters to evaluate the performance of imaging systems. Also, it can be used to restore information that is lost by a harsh space environment (radioactivity, extreme cold/heat condition and electromagnetic field etc.), atmospheric effects and falloff of system performance etc. This paper evaluated the MTF values of images taken by DubaiSat-1 satellite which was launched in 2009 by EIAST(Emirates Institute for Advanced Science and Technology) and Satrec Initiative. Generally, the MTF was assessed using various methods such as a point source method and a knife-edge method. This paper used the slanted-edge method. The slantededge method is the ISO 12233 standard for the MTF measurement of electronic still-picture cameras. The method is adapted to estimate the MTF values of line-scanning telescopes. After assessing the MTF, we performed the MTF compensation by generating a MTF convolution kernel based on the PSF(point spread function) with image denoising to enhance the image quality.

• Journal of the Korean Society of Costume
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• v.56 no.8 s.108
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• pp.83-94
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• 2006

In this era of ubiquitous service, a computing device has functions similar with human beings. It influences all major fields of human life, such as clothing, dieting and housing. In order to use the coordination functions of the magic mirror, which might be a basic part of clothing in the era of ubiquitous service, this study concentrates on product information that should be inputted in RFID chip in detail in order to exercise virtual fashion coordination. Information should be inputted in RFID chip to use magic mirror for fashion coordination, a direction for doing this was also suggested. After coding the suggested clothing items, virtual fashion coordination was implemented as a fashion illustration. This study is as following, First, sorts standard code for suitable coordination in 4 images and presented to a proof. Code denoted by 10 characters. Each code literal special quality marks by two characters and divided by season, image, fabric, item, rotor, five items. Item middle of characters of 10 code, when agree on article more than 8, coordination is enabled. Secondely, It is presented by coordination to dressing action picture by suitable coordination classified apart in whole occasions, and coordination method by wearer inclination is remembered wearer's dressing action picture to Magic mirror including layered look. Thirdly, wardrobe of Magic mirror clothes that always buy newly in magic mirror, is washing and clothes that do not take to wardrobe did to be controlled. Fourth, Wealth and schedule is suggested firster than wearer's dressing action.

• Journal of Broadcast Engineering
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• v.2 no.1
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• pp.8-15
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• 1997

In this paper, a real-time operating Motion Picture Experts Group-1 (MPEG-1) audio encoder system is implemented using a TMS320C31 Digital Signal Processor (DSP) chip. The basic operation of the MPEG-1 audio encoder algorithm based on audio layer-2 and psychoacoustic model-1 is first verified by C-language. It is then realized using the Texas Instruments (Tl) assembly in order to reduce the overall execution time. Finally, the actual BSP circuit board for the encoder system is designed and implemented. In the system, the side-modules such as the analog-to-digital converter (ADC) control, the input/output (I/O) control, the bit-stream transmission from the DSP board to the PC and so on, are utilized with a field programmable gate array (FPGA) using very high speed hardware description language (VHDL) codes. The complete encoder system is able to process the stereo audio signal in real-time at the sampling frequency 48 kHz, and produces the encoded bit-stream with the bit-rate 192 kbps. The real-time operation capability of the encoder system and the good quality of the decoded sound are also confirmed using various types of actual stereo audio signals.

• Journal of Broadcast Engineering
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• v.12 no.3
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• pp.278-288
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• 2007

We propose the fast full search algorithm that reduces the computational load of the block matching algorithm which is used for a motion estimation in the video coding. Since the conventional spiral search method starts searching at the center of the search window and then moves search point to estimate the motion vector pixel by pixel, it is good for the slow motion picture. However we proposed the efficient motion estimation method which is good for the fast and slow motion picture. Firstly, when finding the initial threshold value, we use the expanded predictor that can approximately calculate minimum threshold value. The proposed algorithm estimates the motion in the new search order after partitioning the search window and adapt the directional search order in the re-divided search window. At the result, we can check that the proposed algorithm reduces the computational load 94% in average compared to the conventional spiral full search algorithm without any loss of image quality.

• Journal of the Korea Society of Computer and Information
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• v.15 no.7
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• pp.27-32
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• 2010

We can cut and paste portions of MPEG coded bitstream efficiently to rearrange the audio and video sequences using our proposed method. The proposed method decodes the MPEG stream within just only one GOP(Group of Picture), edits the decoded video frames, and encodes it back to a MPEG stream. In this method, precise editing is possible. A pre-processing step is specially designed to provide easy cut and paste processing. In the pre-processing step for editing MPEG streams, the detail information is extracted. In addition, video quality is not degraded after the proposed editing process is applied. Consequently, the experimental results show significant improvements compared with traditional algorithms for video editing method in terms of the efficiency and exactness.

• Journal of Broadcast Engineering
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• v.12 no.6
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• pp.542-554
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• 2007

Seamless streaming of multimedia content via heterogeneous networks to viewers using a variety of devices has been a desire for many multimedia services, for which the multimedia contents should be adapted to usage environments such as network characteristics, terminal capabilities, and user preferences. Scalability in video coding is one of attractive features to meet dynamically changing requirements of heterogeneous networks. Currently a new scalable video coding (SVC) is standardizing in the Joint Video Team (JVT) of the ISO/IEC Moving Picture Experts Group (MPEG) and the ITU-T Video Coding Experts Group (VCEG), which will be released as Extension 3 of H.264/MPEG-4 AVC. In this paper, we introduce new technologies of SVC and evaluate performance of it especially regarding on overhead bit-rate and coding efficiency to support spatial, temporal, and quality scalability.