• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.47 no.6
• /
• pp.66-74
• /
• 2010

Recently distributed video coding (DVC) is spotlighted for the environment which has restriction in computing resource at encoder. Wyner-Ziv (WZ) coding is a representative scheme of DVC. The WZ encoder independently encodes key frame and WZ frame respectively by conventional intra coding and channel code. WZ decoder generates side information from reconstructed two key frames (t-1, t+1) based on temporal correlation. The side information is regarded as a noisy version of original WZ frame. Virtual channel noise can be removed by channel decoding process. So the performance of WZ coding greatly depends on the performance of channel code. Among existing channel codes, Turbo code and LDPC code have the most powerful error correction capability. These channel codes use stochastically iterative decoding process. However the iterative decoding process is quite time-consuming, so complexity of WZ decoder is considerably increased. Analysis of the complexity of LPDCA with real video data shows that the portion of complexity of LDPCA decoding is higher than 60% in total WZ decoding complexity. Using the HDA (Hard Decision Aided) method proposed in channel code area, channel decoding complexity can be much reduced. But considerable RD performance loss is possible according to different thresholds and its proper value is different for each sequence. In this paper, we propose an adaptive HDA method which sets up a proper threshold according to sequence. The proposed method shows about 62% and 32% of time saving, respectively in LDPCA and WZ decoding process, while RD performance is not that decreased.

• Journal of Broadcast Engineering
• /
• v.13 no.6
• /
• pp.892-904
• /
• 2008

As a video encoding in resource constrained environments such as sensor networks has become an important issue, DVC(Distributed Video Coding) has been intensively investigated as a solution for light weighted video encoding problem. Known as one of the representative schemes of DVC, the Wyner-Ziv coding generates side information of current frame only at decoder, using correlation among frames, and reconstructs video through noise elimination on the side information using channel code. Accordingly, the better quality of side information brings less channel noise, thus attains better coding performance of the Wyner-Ziv coder. However, since it is hard for decoder to generate an accurate side information without any information of original frame, a method to successively improve side information using successively decoded original frame, based on decoding reliability, was previously developed. However, to improve side information from decoding results, not only an error rate of the decoding result as a reliability, but also the amount of reliable information from the decoding result is important. Therefore, we propose TDWZ(Transform-domain Wyner-Ziv coding) with successively improving side information based on decoding reliability considering not only an error rate but also the amount of reliable information of the decoding results. Our experiment shows the proposed method gains average PSNR up to 1.7 dB over the previous TDWZ, that is without successive side information improvement.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.48 no.4
• /
• pp.107-115
• /
• 2011

In this paper, we proposed fast and efficient algorithm for detecting near-duplication based on content based retrieval in large scale video database. For handling large amounts of video easily, we split the video into small segment using scene change detection. In case of video services and copyright related business models, it is need to technology that detect near-duplicates, that longer matched video than to search video containing short part or a frame of original. To detect near-duplicate video, we proposed motion distribution and frame descriptor in a video segment. The motion distribution descriptor is constructed by obtaining motion vector from macro blocks during the video decoding process. When matching between descriptors, we use the motion distribution descriptor as filtering to improving matching speed. However, motion distribution has low discriminability. To improve discrimination, we decide to identification using frame descriptor extracted from selected representative frames within a scene segmentation. The proposed algorithm shows high success rate and low false alarm rate. In addition, the matching speed of this descriptor is very fast, we confirm this algorithm can be useful to practical application.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.49 no.2
• /
• pp.113-121
• /
• 2012

In this paper, we proposed fast and efficient algorithm for detecting near-duplication based on content based retrieval in large scale video database. For handling large amounts of video easily, we split the video into small segment using scene change detection. In case of video services and copyright related business models, it is need to technology that detect near-duplicates, that longer matched video than to search video containing short part or a frame of original. To detect near-duplicate video, we proposed motion distribution and frame descriptor in a video segment. The motion distribution descriptor is constructed by obtaining motion vector from macro blocks during the video decoding process. When matching between descriptors, we use the motion distribution descriptor as filtering to improving matching speed. However, motion distribution has low discriminability. To improve discrimination, we decide to identification using frame descriptor extracted from selected representative frames within a scene segmentation. The proposed algorithm shows high success rate and low false alarm rate. In addition, the matching speed of this descriptor is very fast, we confirm this algorithm can be useful to practical application.

• Journal of Broadcast Engineering
• /
• v.13 no.2
• /
• pp.188-199
• /
• 2008

In conventional video coding, encoder complexity is much higher than that of decoder. However, investigations for lightweight encoder to eliminate motion prediction/compensation claiming most complexity in encoder have recently become an important issue. The Wyner-Ziv coding is one of the representative schemes for the problem and, in this scheme, since encoder generates only parity bits of a current frame without performing any type of processes extracting correlation information between frames, it has an extremely simple structure compared to conventional coding techniques. However, in Wyner-Ziv coding, channel decoding errors occur when noisy side information is used in channel decoding process. These channel decoding errors appear more frequently, especially, when there is not enough correlation between frames to generate accurate side information and, as a result, those errors look like Salt & Pepper type noise in the reconstructed frame. Since this noise severely deteriorates subjective video quality even though such noise rarely occurs, previously we proposed a computationally extremely light encoding method based on selective median filter that corrects such noise using spatial correlation of a frame. However, in the previous method, there is a problem that loss of texture from filtering may exceed gain from error correction by the filter for video sequences having complex torture. Therefore, in this paper, we propose an improved lightweight encoding method that minimizes loss of texture detail from filtering by allowing information of texture and that of noise in side information to be utilized by the selective median filter. Our experiments have verified average PSNR gain of up to 0.84dB compared to the previous method.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.37 no.2
• /
• pp.103-110
• /
• 2024

In this study, a nonlinear dynamic analysis of a frame and single member, which reflect the characteristics of a plant facility, is performed using the commercial MIDAS GEN program and the results are analyzed. The general structural members and material properties of the plant are considered. The Newmark average-acceleration numerical-analysis method is applied to a plastic hinge to study material nonlinearity. The blast load of a vapor-cloud explosion, a representative plant explosion, is calculated, and nonlinear dynamic analysis is conducted on a frame and single member. The observed dynamic behavior is organized according to the ratio of natural period to load duration, maximum displacement, ductility, and rotation angle. The conditions and range under which the frame functions as a single member are analyzed and derived. NSFF with a beam-column stiffness ratio of 0.5 and ductility of 2.0 or more can be simplified and analyzed as FFC, whereas NSPF with a beam-column stiffness ratio of 0.5 and ductility of 1.5 or more can be simplified and analyzed as FPC. The results of this study can serve as guidelines for the blast-resistant design of plant facilities.

• Journal of KIISE:Software and Applications
• /
• v.27 no.5
• /
• pp.510-520
• /
• 2000

For content-based video indexing and retrieval, it is necessary to segment video data into video shots and then select key frames or representative frames for each shot. However, it is very difficult to select key frames automatically because the task of selecting meaningful frames is quite subjective. In this paper, we propose a new approach in selecting key frames based on visual contents such as region information and their temporal variations in the shot. First of all, we classify video shots into panning shots, zooming shots, tilting shots or no camera motion shots by detecting camera motion information in video shots. Then, in each category, we apply appropriate fuzzy rules to select key frames based on meaningful content in frame. Finally, we control the number of key frames in the selection process by adjusting the degree of detail in representing video shots.

• Journal of architectural history
• /
• v.23 no.4
• /
• pp.91-100
• /
• 2014

There are lots of and kinds of stone pagoda and stone Buddhas at Unjusa Temple in Hwasun, Jeonnam, which is thus called as Cheontap(千塔) or Cheonbul.(千佛) Several archaeological excavations have been conducted in Unjusa though, the foundation purpose or background motivation is yet wrapped in mystery. Circular shape is representative pagoda of Unjusa made of round frame or spherical roof but circular stone pagoda is unusual that there is no similar example found in India or China as well as in Korea. Located in the symbolic center, Circular stone pagoda is a key to understand Unjusa. Yundeung(輪燈) is made of stone for circular stone pagoda and there are craft lamp and large lamp. The large lamp, for the palace courtyard on the occasion of Palgwanhoe,(八關會) consists of discs and light on each disc. Outdoor lamp of circular stone pagoda made of stone for permanent preservation purpose. Unjusa is a very special temple with stone-yundeung for circular stone pagoda. In this study, a circular stone pagoda that is the source of yundeung said. Unjusa circular stone pagoda next to the title of 'yundeung pagoda' and proposes to call.

• Journal of architectural history
• /
• v.26 no.1
• /
• pp.93-104
• /
• 2017

This study is about the Changdeokgung Palace and detached palaces of architect Park Jacheong who was a representative supervisor having framed the palace architecture of the Joseon Dynasty. The results are as follows. First, Park Jacheong had been in charge of Changdeokgung Palace for 15 years since its founding. The palace was continued to run for the longest time and was the palace on the frame made by him for the years, so Changdeokgung Palace's status has become as good as Gyeongbokgung Palace's. Second, he built a lot of palaces besides Changdeokgung. They were completed about the same time in accordance with the political intentions of King Taejong. Park Jacheong was a former military officer and was well skilled in mobilization of manpower and materials by making good use of the military power. Third, the detached palaces constructed by him were located in the places where military training and testing of new weapons were possible. They were also used as sleeping, dining and office spaces. This can be regarded as a result of the tradition of the storied-pavilion that had been since the Goryeo Dynasty, with the method of approaching to the main hall of the palace.

• Journal of the Korea Society of Computer and Information
• /
• v.23 no.8
• /
• pp.9-16
• /
• 2018

In this paper, a kidnapping detection scheme in which human pose estimation is used to classify accurately between kidnapping cases and normal ones is proposed. To estimate human poses from input video, human's 10 joint information is extracted by OpenPose library. In addition to the features which are used in the previous study to represent the size change rates and the regularities of human activities, the human pose estimation features which are computed from the location of detected human's joints are used as the features to distinguish kidnapping situations from the normal accompanying ones. A frame-based kidnapping detection scheme is generated according to the selection of J48 decision tree model from the comparison of several representative classification models. When a video has more frames of kidnapping situation than the threshold ratio after two people meet in the video, the proposed scheme detects and notifies the occurrence of kidnapping event. To check the feasibility of the proposed scheme, the detection accuracy of our newly proposed scheme is compared with that of the previous scheme. According to the experiment results, the proposed scheme could detect kidnapping situations more 4.73% correctly than the previous scheme.