A Spatially Adaptive Gradient-Projection Algorithm to Remove Coding Artifacts of H.264

CHOI, Kwon-Yul,HONG, Min-Cheol The Institute of Electronics, Information and Comm 2011 IEICE transactions on information and systems Vol.94 No.5

<P>In this paper, we propose a spatially adaptive gradient-projection algorithm for the H.264 video coding standard to remove coding artifacts using local statistics. A hybrid method combining a new weighted constrained least squares (WCLS) approach and the projection onto convex sets (POCS) approach is introduced, where weighting components are determined on the basis of the human visual system (HVS) and projection set is defined by the difference between adjacent pixels and the quantization index (QI). A new visual function is defined to determine the weighting matrices controlling the degree of global smoothness, and a projection set is used to obtain a solution satisfying local smoothing constraints, so that the coding artifacts such as blocking and ringing artifacts can be simultaneously removed. The experimental results show the capability and efficiency of the proposed algorithm.</P>

Low Computing Loop Filter to Simultaneously Reduce Blocking and Ringing Artifacts for H.264 Video Coding Standard

Kwon Yul Choi,Myoung-Jin Kim,Min-Cheol Hong 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7

we introduce a low computing loop filter to reduce the blocking and ringing artifacts for H.264 video coding standard. One-dimensional regularized smoothing function and regularization parameters are newly defined. The experiment result shows the low computing complexity with similar performance.

H.264 동영상 표준 부호화 방식의 블록화 현상 제거를 위한 적응적 후처리 기법

최권열(Kwon Yul Choi),서강준(Kang Joon Seo),홍민철(Min-Cheol Hong) 한국통신학회 2007 한국통신학회 학술대회논문집 Vol.2007 No.7

H.264 동영상 표준 부호화 방식의 블록화 현상 제거를 위한 적응적 후처리 기법

최권열(Kwon Yul Choi),홍민철(Min-Cheol Hong) 한국통신학회 2008 韓國通信學會論文誌 Vol.33 No.8C

본 논문에서는 H.264 동영상 표준 부호화 방식의 블록화 현상 제거 및 화질 개선을 위한 적응적 후처리 기법에 대해 제안한다. H.264의 루프 필터는 부호화기 내부에 위치함에 따라 부호화 복잡도를 증가시키고, 블록화 현상을 완벽히 제거하지 못하며, 영상을 과도하게 열화 시킨다. 따라서 본 논문에서는 부호화기의 복잡도를 낮추는 동시에 고화질의 영상을 복원하기 위해 Constraint Least Squares(CLS) 기법과 투영 기법을 결합하였다. 또한 인간의 시각 시스템을 반영하기 위해 가중치 norm CLS 기법을 사용하였으며, 이를 위해 블록 경계와 블록 내부에 위치한 화소들의 위치에 따라 각기 다른 국부 분산과 라플라시안 연산자를 새롭게 정의하였다. 국부 화소들은 높은 상관관계를 갖는다는 특성을 이용하여 투영 기법을 위한 투영 집합을 정의하였다. 끝으로 H.264의 양자화 인덱스(QP)를 완화도 조절을 위해 공통적으로 사용하였다. 실험 결과를 통해 제안된 후처리 기법이 H.264의 루프필터보다 블록화 현상을 효과적으로 제거하는 동시에 CLS 기법보다 빠르게 수렴함을 확인할 수 있었다. In this paper, we present a spatially adaptive post-processing algorithm for H.264 video coding standard to remove blocking artifacts. The loop filter of H.264 increases computational complexity of the encoder. Furthermore it doesn't clearly remove the blocking artifacts, resulting in over-blurring. For overcoming them, we combine the projection method with the Constraint Least Squares(CLS) method to restore the high quality image. To reflect the Human Visual System, we adopt the weight norm CLS method. Particularly pixel location-based local variance and laplacian operator are newly defined for the CLS method. In addition, the fact that correlation among adjoining pixels is high is utilized to constrain the solution space when the projection method is applied. Quantization Index(QP) of H.264 is also used to control the degree of smoothness. The simulation results show that the proposed post-processing filter works better than the loop filter of H.264 and converges more quickly than the CLS method.

다중 정규화 매개 변수를 이용한 혼합 norm 영상 복원 방식

최권열(Kwon Yul Choi),김명진(Myoung-Jin Kim),홍민철(Min-Cheol Hong) 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.11C

본 논문에서는 다중 정규화 매개 변수를 이용한 혼합 norm 영상 복원 방식을 제안한다. 임의의 분포를 갖는 첨가 노이즈를 효율적으로 제거하기 위해 정규화 완화 ℓ₂ 함수와 정규화 완화 ℓ₄ 함수를 결합한 새로운 혼합 norm 정규화 완화 함수가 유도된다. 각 완화 함수의 완화도를 제어하기 위해 개별적인 정규화 매개 변수가 정의되고, 정규화 완화 ℓ₂ 함수와 정규화 완화 ℓ₄ 함수의 상대적 기여도를 제어하기 위한 혼합 norm 정규화 매개 변수가 kurtosis를 이용해 정의된다. 안정적인 해를 얻기 위해 반복기법이 사용되었으며, 이들의 수렴 여부가 분석되었다. 다양한 분포를 갖는 첨가 노이즈가 실험에 사용되었으며, 이를 통해서 제안된 방식의 성능을 평가할 수 있었다. In this paper, we propose an iterative mixed norm image restoration algorithm using multi regularization parameters. A functional which combines the regularized ℓ₂ norm functional and the regularized ℓ₄ norm functional is proposed to efficiently remove arbitrary noise. The smoothness of each functional is determined by the regularization parameters. Also, a regularization parameter is used to determine the relative importance between the regularized ℓ₂ norm functional and the regularized ℓ₄ norm functional using kurtosis. An iterative algorithm is utilized for obtaining a solution and its convergence is analyzed. Experimental results demonstrate the capability of the proposed algorithm.

아버지의 성 상동형(sex-role stereotype)과 아동의 성 상동형과의 관계연구

권은정,김연신,노명희,박영미,원경록,이경열,이계숙,이진용,임희진,최여정,최혜영,홍성애 연세대학교 생활과학대학 1987 婦學 Vol.20 No.-

The purpose of this study was to explore the relationship between the sex-role stereotype of the father and the child. We investigated the following: ⑴ Is there a relationship between the sex-role stereotype of the father and the child? ⑵ Is the age of the child a variable in the relationship between the sex-role stereotype of the father and the child? ⑶ Is the sex of the child a variable in the relationship between the sex-role stereotype of the father and the child? The subjects were 193 13-year-old students attending a middle school in Seoul and their fathers and 70 5-year-olds attending a kindergarten in Kwachon and their fathers. The test for the 193 middle school students and their fathers was the Likert Scale of the Bem Sex-Role Inventory which was utilized by the experimenters after a pretest. The instrument for the 5-year-olds was the 22 story-picture card Williams and Bunnett test(1975) modified by Lee, Sook(1982). The kindergarten fathers were tested with the same instrument as the middle school fathers. The data from these 2 tests were then compared using χ^2 test and percent(%). The result of this study were: ⑴ A relationship between the sex-role stereotype of the father and the child was found only between the sex-role stereotype of the middle school students and their fathers. ⑵ Age of the child was found to be a variable in the relationship between the sex-role stereotype of the father and the child. That is, a significant relationship was found between the sex-role stereotype of the middle school students and their fathers, but not between the sex-role stereotype of the preschool children and their fathers. ⑶ Sex of the child was found to be a variable in the relationship between the sex-role stereotype of the father and the child. That is, a significant relationship was found between the sex-role stereotype of the middle school boys and their fathers, but not between the sex-role stereotype of the middle school girls and their fathers.

User friendly molecular breeding platform by analyzing soybean genomes

Yul Ho Kim,Tae-Young Hwang,Hyang Mi Park,Seuk Ki Lee,Man Soo Choi,Kwang Ho Jeong,Min Jung Seo,Hong Tai Yun,Sun Lim Kim,Young-Up Kwon,Ik-Young Choi,Ho-Sung Yoon,Suk-Ha Lee,Jong Bhak,Sunghoon Lee 한국육종학회 2012 한국육종학회 심포지엄 Vol.2012 No.07

Resequencing data is actively used for searching QTL or analyzing genetic diversity in the crops. However, the complexity of genome, caused by genome duplication, limits the utility of genome-wide association studies and linkage analyses to identify genes that regulate agronomically valuable traits. Here, we propose a comparative genomics approach based on core or common variation-based recombination blocks (CRB) using single nucleotide variation (SNV) density information. We found that the soybean genomes are assembled with long and distinct CRBs as large as 10Mb. CRB-based comparative genomics enabled us to accurately identify recombination blocks at the whole-chromosome level. We identified the Ih locus that determines the yellow hilum color in soybeans using CRB-based mapping with representative indel markers. These results suggest that the CRB-based comparison method is a promising platform for molecular breeding and map-based cloning.

Sequence and gene organization of 24 circles from the Cotesia plutellae bracovirus genome

Choi, Jae Young,Kwon, Soo-Jin,Roh, Jong Yul,Yang, Tae Jin,Yoon, Sook Hee,Kim, Heebal,Li, Ming Shun,Park, Beom-Seok,Woo, Soo-Dong,Jin, Byung Rae,Kim, Yonggyun,Je, Yeon Ho Springer-Verlag 2009 Archives of virology Vol.154 No.8

A variant block-based comparative genomics method for the detection of functional loci in soybeans

Yul Ho Kim,Tae-Young Hwang,Hyang Mi Park,Seuk Ki Lee,Man Soo Choi,Seung woo Hwang,Kwang Ho Jeong,Min Jung Seo,Hong Tai Yun,Sun Lim Kim,Young-Up Kwon,Ho-Sung Yoon,Suk-Ha Lee,JongBhak,Sunghoon Lee 한국육종학회 2013 한국육종학회 심포지엄 Vol.2013 No.07

Although much effort has been made to find agronomically important loci in the soybean plant, extensive linkage disequilibrium and genome duplication have limited efficient genome-wide linkage analyses that can identify important regulatory genes. In this respect, recombination block-based analysis of cultivated plant genomes is a potential critical step for molecular breeding and target locus screening. We propose a new three-step method of detecting recombination blocks and comparative genomics of bred cultivars. It utilizes typical reshuffling features of their genomes, which have been generated by the recombination processes of breeding ancestral genomes. To begin with, mutations were detected by comparing genomes to a reference genome. Next, sequence blocks were examined for likenesses and difference with respect to the reference genome. The boundaries between the blocks were taken as recombination sites. All recombination sites found in the cultivar set were used to split the genomes, and the resulting sequence fragments were named as core recombination blocks (CRBs). Finally, the genomes were compared at the CRB level, instead of at the sequence level. In the genomes of the five Korean soybean cultivars used, the CRB-based comparative genomics method produced long and distinct CRBs that are as large as 22.9 Mb. We also demonstrated efficiency in detecting functionally useful target loci by using indel markers, each of which represents a CRB. We further showed that the CRB method is generally applicable to both monocot and dicot crops, by analyzing publicly available genomes of 31 soybeans and 23 rice accessions.

Analysis of promoter activity of selected Cotesia plutellae bracovirus genes

Choi, Jae Young,Kwon, Soo-Jin,Roh, Jong Yul,Yang, Tae-Jin,Li, Ming Shun,Park, Beom-Seok,Kim, Yonggyun,Woo, Soo-Dong,Jin, Byung Rae,Je, Yeon Ho Microbiology Society 2009 The Journal of general virology Vol.90 No.5

<P>In a previous study, we cloned 27 discrete genome segments of Cotesia plutellae bracovirus (CpBV) and provided the complete nucleotide sequences and annotation. Seven putative coding regions were predicted from one of the largest segments, CpBV-S30. The activity of promoters associated with six predicted ORFs from this segment were investigated using both transient and baculovirus expression assays with enhanced green fluorescent protein as a reporter gene. CpBV promoters showed activity earlier than the polyhedrin promoter and the activity of some of these promoters was superior to that of the Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ie-1 promoter in the baculovirus expression assays. The promoter of ORF3004 showed the highest level of activity in insect cells, exhibiting 24 % of the activity obtained with the AcMNPV polyhedrin promoter in Sf9 cells. In Spodoptera exigua larvae, the ORF3006 promoter showed the highest activity, with about 35 % of the activity measured with the polyhedrin promoter. In addition, analysis of the ORF3006 promoter revealed that the region between -382 and -422 from the translation start point was critical for activity of this promoter. These results suggest that the CpBV-S30 promoters characterized here could be useful tools in a variety of biotechnological applications, such as gene expression analyses and insecticide development.</P>