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Low-Complexity H.264/AVC Deblocking Filter based on Variable Block Sizes (가변블록 기반 저복잡도 H.264/AVC 디블록킹 필터)

  • Shin, Seung-Ho;Doh, Nam-Keum;Kim, Tae-Yong
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.4
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    • pp.41-49
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    • 2008
  • H.264/AVC supports variable block motion compensation, multiple reference images, 1/4-pixel motion vector accuracy, and in-loop deblocking filter, compared with the existing compression technologies. While these coding technologies are major functions of compression rate improvement, they lead to high complexity at the same time. For the H.264 video coding technology to be actually applied on low-end / low-bit rates terminals more extensively, it is essential to improve tile coding speed. Currently the deblocking filter that can improve the moving picture's subjective image quality to a certain degree is used on low-end terminals to a limited extent due to computational complexity. In this paper, a performance improvement method of the deblocking filter that efficiently reduces the blocking artifacts occurred during the compression of low-bit rates digital motion pictures is suggested. In the method proposed in this paper, the image's spatial correlational characteristics are extracted by using the variable block information of motion compensation; the filtering is divided into 4 modes according to the characteristics, and adaptive filtering is executed in the divided regions. The proposed deblocking method reduces the blocking artifacts, prevents excessive blurring effects, and improves the performance about $30{\sim}40%$ compared with the existing method.

View Synthesis Error Removal for Comfortable 3D Video Systems (편안한 3차원 비디오 시스템을 위한 영상 합성 오류 제거)

  • Lee, Cheon;Ho, Yo-Sung
    • Smart Media Journal
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    • v.1 no.3
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    • pp.36-42
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    • 2012
  • Recently, the smart applications, such as smart phone and smart TV, become a hot issue in IT consumer markets. In particular, the smart TV provides 3D video services, hence efficient coding methods for 3D video data are required. Three-dimensional (3D) video involves stereoscopic or multi-view images to provide depth experience through 3D display systems. Binocular cues are perceived by rendering proper viewpoint images obtained at slightly different view angles. Since the number of viewpoints of the multi-view video is limited, 3D display devices should generate arbitrary viewpoint images using available adjacent view images. In this paper, after we explain a view synthesis method briefly, we propose a new algorithm to compensate view synthesis errors around object boundaries. We describe a 3D warping technique exploiting the depth map for viewpoint shifting and a hole filling method using multi-view images. Then, we propose an algorithm to remove boundary noises that are generated due to mismatches of object edges in the color and depth images. The proposed method reduces annoying boundary noises near object edges by replacing erroneous textures with alternative textures from the other reference image. Using the proposed method, we can generate perceptually inproved images for 3D video systems.

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A H.264 based Selective Fine Granular Scalable Coding Scheme (H.264 기반 선택적인 미세입자 스케일러블 코딩 방법)

  • 박광훈;유원혁;김규헌
    • Journal of KIISE:Computing Practices and Letters
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    • v.10 no.4
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    • pp.309-318
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    • 2004
  • This paper proposes the H.264-based selective fine granular scalable (FGS) coding scheme that selectively uses the temporal prediction data in the enhancement layer. The base layer of the proposed scheme is basically coded by the H.264 (MPEG-4 Part 10 AVC) visual coding scheme that is the state-of-art in codig efficiency. The enhancement layer is basically coded by the same bitplane-based algorithm of the MPEG-4 (Part 2) fine granular scalable coding scheme. In this paper, we introduce a new algorithm that uses the temproal prediction mechanism inside the enhancement layer and the effective selection mechanism to decide whether the temporally-predicted data would be sent to the decoder or not. Whenever applying the temporal prediction inside the enhancement layer, the temporal redundancies may be effectively reduced, however the drift problem would be severly occurred especially at the low bitrate transmission, due to the mismatch bewteen the encoder's and decoder's reference frame images. Proposed algorithm selectively uses the temporal-prediction data inside the enhancement layer only in case those data could siginificantly reduce the temporal redundancies, to minimize the drift error and thus to improve the overall coding efficiency. Simulation results, based on several test image sequences, show that the proposed scheme has 1∼3 dB higher coding efficiency than the H.264-based FGS coding scheme, even 3∼5 dB higher coding efficiency than the MPEG-4 FGS international standard.

Analysis of Mistakes in Photosynthesis Unit in Biology II Textbooks and Survey of Biology Teachers' Recognition on them (생물 II 교과서 광합성 단원의 오류 분석 및 생물 교사의 오류 인지 조사)

  • Park, Hae-Kyung;Yoon, Ki-Soon;Kwon, Duck-Kee
    • Journal of Science Education
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    • v.32 no.1
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    • pp.33-46
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    • 2008
  • The purpose of this study was to know whether or not any wrongful description or simple errors were in photosynthesis unit of Biology II textbook under 7th national curriculum and if so, to know whether or not high school teachers recognized and corrected properly the mistakes. The mistakes in photosynthesis unit of text books were determined by the comparison with several reference books and through examination by three plant physiologists in 8 different Biology II textbooks. After the mistakes were analysed, the survey using contents of textbook containing the mistakes was conducted on high school teachers teaching Biology II. As a result, 48 mistakes were determined in 13 subjects. As many as four mistakes were found even in one subject in a certain textbook and a same mistake was found repeatedly in several textbooks. The survey result showed that the teachers who pointed exactly the mistakes out corrected properly, however, the percentage of these ones out of 35 teachers replied to survey was less than 50%. The ratios of correction out of total number of responses were high in question #6 (43%), #4-3 (40%), and #1-2 (32%) which were containing a simple mistake in graph, a wrong word and a wrong picture, respectively. But, no one pointed out and made correction in question #5-1 and #5-2 which were containing Z scheme of light reaction without the legend of vertical axis that should be explained as electron energy or standard reduction potential. The result indicates the possibility that the mistakes in photosynthesis unit of Biology II textbook can be corrected and teached properly by teachers may be low. In order to reduce the possibility that students may have misconceptions about photosynthesis, the list of print's errors should be provided to the teachers and/or the training program and/or workshop for in-service high school biology teachers was recommended.

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A Study on the Royal Banquet Dishes in Naeoejinyeon-Deungnok in 1902 (「내외진연등록(內外進宴謄錄)」을 통해 본 궁중연회음식의 분석적 고찰 - 1902년 중화전 외진연(外進宴) 대전과 황태자의 상차림을 중심으로 -)

  • Lee, So-Young;Han, Bok-Ryo
    • Journal of the Korean Society of Food Culture
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    • v.27 no.2
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    • pp.128-141
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    • 2012
  • This study focused on the historic documents known as $deungnok$, records created during preparations for royal events in the $Joseon$ Dynasty, rather than the often cited $uigwe$, the documents describing the Royal Protocol of the $Joseon$ Dynasty. As a reference to the food served at royal banquets, the $deungnok$ can enhance our understanding of royal banquet foods. Seven specimens of $deungnok$ describing royal banquet foods are currently in existence, created during preparations for royal events by the agencies in charge of food, the $Saongwon$ and $Jeonseonsa$. Owing to the nature of their authorship, the details recorded in these $deungnok$ hold great value as important resources for the study of royal banquet cuisine. $Naeoejinyeon$-$deungnok$, which documented an $oejinyeon$ banquet held at the $Junghwajeon$ Pavilion in November 1902, was somewhat disorganized and fragmented. $Jinyeonuigwe$ was more inclusive and well-summarized, since the former were progress reports to the King during banquet preparations that listed various items separately, such as dishes for each table setting and the kinds of flower pieces, and thus did not present a complete picture of all the details as a whole. The latter, on the other hand, were final reports created upon completion of a banquet, and contained more comprehensive records not only of the $chanpum$ (the menu of dishes served), but also the sorts of tableware and tables, floral arrangements, location, scale, and installation date of the $sukseolso$ (temporary royal kitchens for banquets). They also offer a more effective summary by simplifying details duplicated in identical table settings. Nevertheless, the $Naeoejinyeon$-$deungnok$ recorded some facts that cannot be gleaned from the $Jinyeonuigwe$, including the height of some dishes presented in piled stacks, as well as the specific names of dishes and their ingredients. The comparative study of the historic records in the $deungnok$ and $uigwe$ will be helpful in identifying and understanding the specific foods served at royal banquets. The $oejinyeon$-$seolchando$ diagrams in $Naeoejinyeon$-$deungnok$ depict the table settings for the King and the Crown Prince. The two diagrams contain large rectangles divided into three sections. In each section are similar-sized circles in which the names of dishes and the titles for table settings are recorded. From these records we can see that the arrangements of the table settings for the King and the Crown Prince are similar. The relationships and protocols shown in the arrangement of dishes and table settings for the King and the Crown Prince at royal banquets in the $Seolchando$ appear to be consistent. By comparing the two references, $deungnok$ and $uigwe$, which recorded the dishes served at royal banquets, the author was able to determine the height of some foods served in stacked arrangements, the names of $chanpum$, the ingredients used, and the configuration of the $chanpum$. The comparative review of these two written records, $deungnok$ and $uigwe$, will be helpful for a proper understanding of the actual food served at royal banquets.

Comparative Study on the Dancheong(丹靑) of Buddhist Temples in Jeolla Region focused on the Dancheong of the main building of Mihwangsa Buddhist Temple at Haenam(海南) (전라도지역 사찰단청(寺刹丹靑)의 비교 연구 해남 미황사(美黃寺) 대웅전(大雄殿) 단청을 중심으로)

  • Lee, Su Yee
    • Korean Journal of Heritage: History & Science
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    • v.42 no.4
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    • pp.152-171
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    • 2009
  • The Dancheong(丹靑) of the main building of Mihwangsa Buddhist Temple(美黃寺) in Haenam(海南) is the leading work of the Jeolla Dancheong style, which was created in the 18th century and has been passed down to the early modern days, and boasts its excellence and originality. On the outside, one can only see the traces of the Dancheong due to the colors that fell off and deteriorated severely. On the inside, however, the general Dancheong pattern is accompanied by the painting of 1,000 Buddhas(千佛圖), which is hardly found in other Buddhist temples, and the Arahan painting, which is truly magnificent in technique and can pass as an independent painting. The Dancheong also has unique methodological characteristics that can't be found in other Dancheong works such as the painting and attaching technique. The Dancheong inside is estimated to have been created in 1754 considering the records of "Dalmasan Mihwangsasa Daebeopdang Jungsusangryangmun(達摩山美黃寺大法堂重修上樑文)", the calligraphical writings of "Mudeungsanindanhwakya(無等山人丹?也)"and "Geonryungshipgu(乾隆十九)" left in the Jungryang, and the style characteristics reflected in the Dancheong patterns and the painting of 1,000 Buddhas. The fact that there are no traces of re-Dancheong also supports the estimation that the Dancheong was created in the absolute age of 1754. The absolute age will be the reference of deciding the chronological years of Dancheong patterns and be helpful in examining the characteristics and changes by the periods. There were certain style characteristics in Dancheong by the periods and regions. The Dancheong of Jeolla region also had its own style, which includes the tendency of finishing with two- or three-fold green belts without giving meokdanggi to the meoricho and the huge jar decoration of huigol. Treating the baetbadak of all materials, whether it's Geumdancheong or morodancheong, with lines of certain thickness and colors is another style of Jeolla Dancheong from the 18th to the 20th century. The Dancheong of the Geukrakbojeon(極樂寶殿) of Cheoneunsa Buddhist Temple and Daewoongbojeon(大雄寶殿) of Naesosa Buddhist Temple in Jeolla is especially noteworthy in that it bears similar patterns and techniques to that of the main building of Mihwangsa Buddhist Temple in addition to the characteristics mentioned above. The Dancheong of Mihwangsa Buddhist Temple must have exerted so great influences on that of the two temples that it's called "the style of Mihwangsa Buddhist Temple."When adopting a broader point of view, it can be classified as one of the Dancheong styles of Jeolla. The common icons and techniques found in the Dancheong of Mihwangsa, Cheoneunsa, and Naesosa Buddhist Temple provide some clues about the influential relationships among painters of the days. They may have been created by the painters of the same school or the painters affected by those who created the Dancheong of Mihwangsa Buddhist Temple.