• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.5
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• pp.136-146
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• 2012

As information technology used for simulation and virtual reality developed, there is a growing interest in animation technologies which will effectively deliver simulation results to users. Various efforts have been made to improve animation performance, like playback quality and speed, input-output speed and storage space reduction. However, earlier studies generally focused on image compression frame by frame. To significantly improve storage space and playback speed, animation data should be vectorized. Also, spatial and temporal duplication have to be removed. In this study, animation data structure was improved fundamentally through establishment of hierarchy and vectorization. Also Spatial and temporal duplication of animation data was removed through vectorization based on train route. As a result, storage space was reduced, input-output speed and playback speed were considerably improved. According to the test, additional Patternization which followed vectorization brought reduction of over 80% in storage space and input-output speed was quadrupled. Patternization technology can be used as a proper storage method of animation data, and can provide user-specific animation by small data transmission.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10B
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• pp.1912-1920
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• 1999

In this paper, we propose a layered video coding scheme which can generate multi-layered bitstream for heterogeneous environments. A new motion prediction structure with temporal hierarchy of frames is developed to afford temporal resolution scalability and the wavelet decomposition is adopted to offer spatial acalability. The proposed scheme can have a higher compression ratio than replenishment schemes by using motion estimation and compensation which can further reduce the temporal redundancy, and it effectively works with dynamic adaption or errors using dispersive intra-subband update (DISU). Moreover, data rate scalability can be attained by employing embeded zerotree wavelet (EZW) technique which can produce embeded bitstream. Therefore, the proposed scheme is expected to be effectively used in heterogeneous environments such as the Internet, ATM, and mobile networks where interoperability are required.

• Journal of Korea Multimedia Society
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• v.1 no.2
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• pp.194-203
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• 1998

In this paper, a new DCT-VQ method is proposed which can solve the problems of VQ such as the degradation of edge and enormous calculations. VQ is carried in DCT domain but spatial domain in order to protect the degradation of edge. DCT makes high correlated image data decorrelated and the energy concentrated on a few coefficients. In DCT domain, the DC coefficient is quantized with 8 bits uniform scalar quantizer and the AC coefficients are divided to three regions and coded with vector qiantizer for considering edge components. For the decrease of the calculation and memory, the vectors for three region have small dimension of $1{\times}7$ and use the same codebook. Thus, the proposed method can fully express the edge components by considering AC coefficients in DCT domain and decrease the calculation and memory be reducing the dimension of vectors.

• 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 Broadcast Engineering
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• v.16 no.2
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• pp.372-383
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• 2011

This paper proposes an improved design of an interleaved motion vector coding scheme with flexibility in predictive motion vector component by exploiting motion characteristics. It can use component-wise adaptive motion vector predictor based on the utility of spatial and temporal motion field without any signaling bit for indicating decoder of the selected predictive motion vector component. Experiment with test video data shows about 1.99% (max 8.71%) bit rate reduction compared to the conventional H.264/AVC method.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.5
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• pp.133-143
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• 2019

Various problems regarding the wet floor method such as its complicated process and waste of thermal storage have been raised, but the usage of dry floor recommended for long-life housing has declined due to lack of confidence on the performance of dry floor. The purpose of this study is to secure the credibility of dry floor. Under this purpose, this study considered precedent studies and established directions to secure the performance of long-life housing infill, and thus, 9 performance items (Impact sound, Smoothness, thermal comfort, sensation hardness while walking, falling safety, impact resistance, local compression load, local strength and strain at heating) were drawn. In addition, the experiment was carried out for 5 performances except for legal performance, some dry floor performances and whole spatial performance. As a result, an appropriate result from all performances except was obtained. The performance of dry floor was verified for each item from these results and it is expected to use such results as basic data on dry floor in the future.

• Journal of Broadcast Engineering
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• v.24 no.5
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• pp.849-858
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• 2019

Recent developments in computer graphics technology and image processing technology have increased interest in point cloud technology for inputting real space and object information as three-dimensional data. In particular, point cloud technology can accurately provide spatial information, and has attracted a great deal of interest in the field of autonomous vehicles and AR (Augmented Reality)/VR (Virtual Reality). However, in order to provide users with 3D point cloud contents that require more data than conventional 2D images, various technology developments are required. In order to solve these problems, an international standardization organization, MPEG(Moving Picture Experts Group), is in the process of discussing efficient compression and transmission schemes. In this paper, we provide a region division transfer method of 3D point cloud content through extension of existing MPEG-DASH (Dynamic Adaptive Streaming over HTTP)-SRD (Spatial Relationship Description) technology, quality parameters are further defined in the signaling message so that the quality parameters can be selectively determined according to the user's request. We also design a verification platform for ROUTE (Real Time Object Delivery Over Unidirectional Transport)/DASH based heterogeneous network environment and use the results to validate the proposed technology.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.377-379
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• 2020

The hologram data is having a dependence on the pixel pitch of the SLM (spatial light modulator) and the wavelength of light, and the quality of the digital hologram is proportional to the unit pixel pitch and the total resolution. In addition, since each pixel has a complex value, the amount of data in the digital hologram also increases exponentially, and the size is bound to be very large. Therefore, in order to efficiently handle digital hologram files, it is essential to reduce the file size through a codec and store it. Recently, research on enhancing image quality damaged by the codec is actively underway. In this paper, the hologram image of JPEG Pleno, which is the standard hologram data, was used, and the image quality damage that occurs whenthe holographic image is encoded and decoded through the JPEG2000, AVC, and HEVC codec is enhanced with a deep learning network to find out whether the image quality can be improved. we also compare and quantitatively find out the degree of improvement in image quality.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.3
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• pp.29-33
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• 2007

All pixels of image sensor do not react uniformly even if the light of same radiance enters into the camera. This non-uniformity comes from the sensor pixel non-uniformity and non-uniformity induced by the changing transmission of the telescope over the field. The first contribution to the non-uniformity has high spatial frequency nature and has an influence on the result and quality of the data compression. The second source of non-uniformity has low frequency nature and has no influence of the compression result. As the contribution resulting from the sensor PRNU(Photo Response Non-Uniformity) is corrected inside the camera electronics, the effect of the remaining non-uniformity to the compression result will be negligible. The non-uniformity correction result shall have big difference according to the sensor modeling and the calculation method to get correction coefficient. Usually, the sensor can be modeled with one dimensional coefficients which are a gain and a offset for each pixel. Only two measurements are necessary theoretically to get coefficients. However, these are not the optimized value over the whole illumination level. This paper proposes the algorithm to calculate the optimized non-uniformity correction coefficients over whole illumination radiance. The proposed algorithm uses several measurements and the least square method to get the optimum coefficients. The proposed algorithm is verified using the own camera electronics including sensor, electrical test equipment and optical test equipment such as the integrating sphere.

• Journal of Broadcast Engineering
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• v.26 no.6
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• pp.692-703
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• 2021

Recently, with the development of computer graphics technology, research on technology for expressing real objects as more realistic virtual graphics is being actively conducted. Point cloud is a technology that uses numerous points, including 2D spatial coordinates and color information, to represent 3D objects, and they require huge data storage and high-performance computing devices to provide various services. Video-based Point Cloud Compression (V-PCC) technology is currently being studied by the international standard organization MPEG, which is a projection based method that projects point cloud into 2D plane, and then compresses them using 2D video codecs. V-PCC technology compresses point cloud objects using 2D images such as Occupancy map, Geometry image, Attribute image, and other auxiliary information that includes the relationship between 2D plane and 3D space. When increasing the density of point cloud or expanding an object, 3D calculation is generally used, but there are limitations in that the calculation method is complicated, requires a lot of time, and it is difficult to determine the correct location of a new point. This paper proposes a method to generate additional points at more accurate locations with less computation by applying 2D interpolation to the image on which the point cloud is projected, in the V-PCC technology.