• Title/Summary/Keyword: texture compression

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Boundary Artifacts Reduction in View Synthesis of 3D Video System (3차원 비디오의 합성영상 경계 잡음 제거)

  • Lee, Dohoon;Yang, Yoonmo;Oh, Byung Tae
    • Journal of Broadcast Engineering
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    • v.21 no.6
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    • pp.878-888
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    • 2016
  • This paper proposes an efficient method to remove the boundary artifacts of rendered views caused by damaged depth maps in the 3D video system. First, characteristics of boundary artifacts with the compression noise in depth maps are carefully studied. Then, the artifacts suppression method is proposed by the iterative projection onto convex sets (POCS) algorithm with setting the convex set in pixel and frequency domain. The proposed method is applied to both texture and depth maps separately during view rendering. The simulation results show the boundary artifacts are greatly reduced with improving the quality of synthesized views.

Quality Characteristics of kimchi with added Backryeoncho (Opuntia ficus-indica var. saboten) Extract and Its Acceptability by Middle School Students (백련초 추출물 첨가 김치의 품질특성 및 중학교 급식에서의 수응도 평가)

  • Lee, Young-Sook;Rho, Jeong-Ok
    • Korean Journal of Human Ecology
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    • v.21 no.6
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    • pp.1211-1222
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    • 2012
  • This research studied the effects of Backryeoncho (Opuntia ficus-indica var. saboten) extract as an additive in kimchi in various amounts (0%, 0.4%, 0.8%, 1.2%), and its acceptance by middle school students in the Jeonju area. The treated kimchi had a higher pH than the untreated kimchi without extract, and the titratable acidity of the kimchi decreased with the addition of the Backryeoncho extract. The degree of salinity decreased in kimchi with the added Backryeoncho extract in a dose-dependent manner. The cutting force and compression force were higher in kimchi where the extract was added during the fermentation period resulting in improved texture of the kimchi. The addition of the extract slowed growth of total bacteria (1.83~2.12 log CFU/mL) and lactic acid bacteria (1.4 log CFU/mL) as compared with the control sample. In the sensory evaluation of overall taste, kimchi with 0.8% extract added demonstrated higher evaluation in overall categories. The acceptability of Backryeoncho extract as an additive in kimchi among middle school students was higher than in the control sample, with an optimum additive of 0.4% extract, based on the lowest volume of leftovers.

Post-Processing for JPEG-Coded Image Deblocking via Sparse Representation and Adaptive Residual Threshold

  • Wang, Liping;Zhou, Xiao;Wang, Chengyou;Jiang, Baochen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.3
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    • pp.1700-1721
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    • 2017
  • The problem of blocking artifacts is very common in block-based image and video compression, especially at very low bit rates. In this paper, we propose a post-processing method for JPEG-coded image deblocking via sparse representation and adaptive residual threshold. This method includes three steps. First, we obtain the dictionary by online dictionary learning and the compressed images. The dictionary is then modified by the histogram of oriented gradient (HOG) feature descriptor and K-means cluster. Second, an adaptive residual threshold for orthogonal matching pursuit (OMP) is proposed and used for sparse coding by combining blind image blocking assessment. At last, to take advantage of human visual system (HVS), the edge regions of the obtained deblocked image can be further modified by the edge regions of the compressed image. The experimental results show that our proposed method can keep the image more texture and edge information while reducing the image blocking artifacts.

The Effect of the Characteristics of Fabrics and Subjective Sensory Images on the Off-line and On-line Preferences of Women's Suit Fabrics

  • Kim, Hee-Sook;Na, Mi-Hee
    • International Journal of Human Ecology
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    • v.13 no.1
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    • pp.105-115
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    • 2012
  • This research investigated the influences of structural characteristics such as fabrics, mechanical properties, and subjective sensory images on the off-line and on-line preferences to women's spring/summer suits fabrics to extract the most effective factor towards preference as well as analyze the preferential off-line and on-line differences to predict the exact texture image on-line. Objective evaluations were done for the measurement of the mechanical properties of fabrics using Kawabata's Evaluation System and subjective evaluations were done with 109 female subjects who value the off-line and on-line sensory image of suit fabrics. For statistical analysis, factor analysis, cluster analysis, t-test, ANOVA, and regression were used. The results were as follows. The preference scores on-line were generally higher than those off-line. For the structural characteristics of fabrics, differences of thickness were observed according to preference clusters, and the preference increased as thickness was lowered off-line and on-line. For mechanical properties, WC influenced off-line and on-line preferences. Fabrics with low compression energy were preferred; however, the effect of SMD was observed off-line only. In subjective sensory images, the 'smoothness' image influenced off-line and on-line preferences the most. All sensory images influenced the off-line preferences; however, the effects of 'flexibility' and 'weight' were not shown on-line.

Fast Algorithm for Intra Prediction of HEVC Using Adaptive Decision Trees

  • Zheng, Xing;Zhao, Yao;Bai, Huihui;Lin, Chunyu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.7
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    • pp.3286-3300
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    • 2016
  • High Efficiency Video Coding (HEVC) Standard, as the latest coding standard, introduces satisfying compression structures with respect to its predecessor Advanced Video Coding (H.264/AVC). The new coding standard can offer improved encoding performance compared with H.264/AVC. However, it also leads to enormous computational complexity that makes it considerably difficult to be implemented in real time application. In this paper, based on machine learning, a fast partitioning method is proposed, which can search for the best splitting structures for Intra-Prediction. In view of the video texture characteristics, we choose the entropy of Gray-Scale Difference Statistics (GDS) and the minimum of Sum of Absolute Transformed Difference (SATD) as two important features, which can make a balance between the computation complexity and classification performance. According to the selected features, adaptive decision trees can be built for the Coding Units (CU) with different size by offline training. Furthermore, by this way, the partition of CUs can be resolved as a binary classification problem. Experimental results have shown that the proposed algorithm can save over 34% encoding time on average, with a negligible Bjontegaard Delta (BD)-rate increase.

An Edge Histogram Descriptor for MPEG-7 (MPEG-7을 위한 에지 히스토그램 서술자)

  • 박동권;전윤석;박수준;원치선
    • Journal of Broadcast Engineering
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    • v.5 no.1
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    • pp.31-40
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    • 2000
  • In this paper, we propose an edge histogram to efficiently represent the edge distribution in the image for MPEG-7. To this end, we adopt global, semi-global, and local edge histogram bins. Also, we extract the edge information from the image in terms of image blocks rather than pixels, which reduces the extraction complexity and is also applicable to the block-based compression standards such as MPEG-1, and 2. Experimental results show that the proposed method yields better retrieval accuracy and feature extraction speed comparing to other non-homogeneous texture descriptors of MPEG-7 including the wavelet-based descriptor and local edge-based descriptor.

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Effects of the Mixed Coagulants Ratio on SPI-Tofu Characteristics (응고제의 혼합비율이 분리대두단백두부의 특성에 미치는 영향)

  • 김동원;고순남;김우정
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.23 no.1
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    • pp.98-103
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    • 1994
  • Some quality characteristics of tofu prepared with soyprotein isolate (SPI) were investigated to study the effects of various ratio of coagulants mixture and addition of oil, sucrose and dextrin. The tofu was prepared by addition of coagulants into the boiled SPI suspension and compression. The results showed that the mixed coagulants of CaCl $_2$-GDL(50 :50) and CaSO$_4$-GDL(25 :75) resulted the highest volume yield of 4.23g/g SPI among the various ratios of CaCl$_2$-CaSO$_4$, CaCl$_2$-GDL and CaSO$_4$-GDL. The water holding capacity(WHC) expressed as the area of water absorbed on filter paper was relatively high for those tofu coagulation with CaCl$_2$-GDL(75 : 25) and CaSO$_4$ -GDL(75 : 25). Addition of sucrose or oil-sucrose (1 : 1) decreased the yield wihle WHC was improved. Their addition also caused less hard and cohesive tofu which was coagulated by CaCl$_2$-GDL(75 : 25) and CaSO$_4$-GDL(75 : 25).

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Context-Based Minimum MSE Prediction and Entropy Coding for Lossless Image Coding

  • Musik-Kwon;Kim, Hyo-Joon;Kim, Jeong-Kwon;Kim, Jong-Hyo;Lee, Choong-Woong
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 1999.06a
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    • pp.83-88
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    • 1999
  • In this paper, a novel gray-scale lossless image coder combining context-based minimum mean squared error (MMSE) prediction and entropy coding is proposed. To obtain context of prediction, this paper first defines directional difference according to sharpness of edge and gradients of localities of image data. Classification of 4 directional differences forms“geometry context”model which characterizes two-dimensional general image behaviors such as directional edge region, smooth region or texture. Based on this context model, adaptive DPCM prediction coefficients are calculated in MMSE sense and the prediction is performed. The MMSE method on context-by-context basis is more in accord with minimum entropy condition, which is one of the major objectives of the predictive coding. In entropy coding stage, context modeling method also gives useful performance. To reduce the statistical redundancy of the residual image, many contexts are preset to take full advantage of conditional probability in entropy coding and merged into small number of context in efficient way for complexity reduction. The proposed lossless coding scheme slightly outperforms the CALIC, which is the state-of-the-art, in compression ratio.

Properties and pozzolanic reaction degree of tuff in cement-based composite

  • Yu, Lehua;Zhou, Shuangxi;Deng, Wenwu
    • Advances in concrete construction
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    • v.3 no.1
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    • pp.71-90
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    • 2015
  • In order to investigate the feasibility and advantage of tuff used as pozzolan in cement-based composite, the representative specimens of tuff were collected, and their chemical compositions, proportion of vitreous phase, mineral species, and rock structure were measured by chemical composition analysis, petrographic analysis, and XRD. Pozzolanic activity strength index of tuff was tested by the ratio of the compression strength of the tuff/cement mortar to that of a control cement mortar. Pozzolanic reaction degree, and the contents of CH and bond water in the tuff/cement paste were determined by selective hydrochloric acid dissolution, and DSC-TG, respectively. The tuffs were demonstrated to be qualified supplementary binding material in cement-based composite according to relevant standards. The tuffs possessed abundant $SiO_2+Al_2O_3$ on chemical composition and plentiful content of amorphous phase on rock texture. The pozzolanic reaction degrees of the tuffs in the tuff/cement pastes were gradually increased with prolongation of curing time. The consistency of CH consumption and pozzolanic reaction degree was revealed. Variation of the pozzolanic reaction degree was enhanced with the bond water content and relationship between them appeared to satisfy an approximating linear law. The fitting linear regression equation can be applied to mutual conversion between pozzolanic reaction degree and bond water content.

Optical Multi-Normal Vector Based Iridescence BRDF Compression Method (광학적 다중 법선 벡터 기반 훈색(暈色)현상 BRDF 압축 기법)

  • Ryu, Sae-Woon;Lee, Sang-Hwa;Park, Jong-Il
    • Journal of KIISE:Computer Systems and Theory
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    • v.37 no.3
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    • pp.184-193
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    • 2010
  • This paper proposes a biological iridescence BRDF(Bidirectional Reflectance Distribution Function) compression and rendering method. In the graphics technology, iridescence sometimes is named structure colors. The main features of these symptoms are shown transform of color and brightness by varying viewpoint. Graphics technology to render this is the BRDF technology. The BRDF methods enable realistic representation of varying view direction, but it requires a lot of computing power because of large data. In this paper, we obtain reflection map from iridescence BRDF, analyze color of reflection map and propose representation method by several colorfully concentric circle. The one concentric circle represents beam width of reflection ray by one normal vector. In this paper, we synthesize rough concentric by using several virtually optical normal vectors. And we obtain spectrum information from concentric circles passing through the center point. The proposed method enables IBR(image based rendering) technique which results is realistic illuminance and spectrum distribution by one texture from reduced BRDF data within spectrum.