• Title/Summary/Keyword: Absolute Disparity

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The Algorithm of Brightness Control Disparity Matching in Stereoscopic (스테레오 스코픽에서 밝기 조정 정합 알고리즘)

  • Song, Eung-Yeol;Kim, Young-Seop
    • Journal of the Semiconductor & Display Technology
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    • v.8 no.4
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    • pp.95-100
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    • 2009
  • This paper presents an efficient disparity matching, using sum of absolute difference (SAD) and dynamic programming (DP) algorithm. This algorithm makes use of one of area-based algorithm which is the absolute sum of the pixel difference corresponding to the window size. We use the information of the right eye brightness (B) and the left eye brightness to get an best matching results and apply the results to the left eye image using the window go by the brightness of the right eye image. This is that we can control the brightness. The major feature of this algorithm called SAD+DP+B is that although Root Mean Square (RMS) performance is slightly less than SAD+DP, due to comparing original image, its visual performance is increased drastically for matching the disparity map on account of its matching compared to SAD+DP. The simulation results demonstrate that the visual performance can be increased and the RMS is competitive with or slightly higher than SAD+DP.

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SIFT-based Stereo Matching to Compensate Occluded Regions and Remove False Matching for 3D Reconstruction

  • Shin, Do-Kyung;Lee, Jeong-Ho;Moon, Young-Shik
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.418-422
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    • 2009
  • Generally, algorithms for generating disparity maps can be clssified into two categories: region-based method and feature-based method. The main focus of this research is to generate a disparity map with an accuracy depth information for 3-dimensional reconstructing. Basically, the region-based method and the feature-based method are simultaneously included in the proposed algorithm, so that the existing problems including false matching and occlusion can be effectively solved. As a region-based method, regions of false matching are extracted by the proposed MMAD(Modified Mean of Absolute Differences) algorithm which is a modification of the existing MAD(Mean of Absolute Differences) algorithm. As a feature-based method, the proposed method eliminates false matching errors by calculating the vector with SIFT and compensates the occluded regions by using a pair of adjacent SIFT matching points, so that the errors are reduced and the disparity map becomes more accurate.

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Estimation of Disparity Map using MMAD and SIFT (MMAD와 SIFT를 이용한 디스패리티 맵 생성)

  • Shin, Do-Kyung;Moon, Young-Shik
    • Proceedings of the Korean Information Science Society Conference
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    • 2007.10c
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    • pp.510-515
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    • 2007
  • 2차원 영상으로부터 3차원 정보를 획득하기 위해서는 disparity map의 정확한 계산이 요구된다. Disparity map을 구하기 위한 기존의 알고리즘은 크게 상관도 기반 방법과 특징 기반 방법으로 분류되는데, 본 논문에서는 이들 각 방법에 대한 분석을 통해서 좀 더 정확한 disparity map을 구하는 방법을 모색한다. 이를 위해 스테레오 카메라로부터 획득된 2차원 영상에서 건물에 대한 깊이 정보 추출을 위해 SIFT 기법을 이용한 disparity map 생성 알고리즘을 제안한다. 제안된 기법은 수정된 MAD인 MMAD(Modified Mean of Absolute Differences) 알고리즘을 새로 제안하여 영역 기반의 유사도 측정을 기반으로 하면서 특징 기반 방법의 하나인 SIFT를 적용하여 거짓 정합(false matching)에 의한 에러를 줄이고 폐색(occlusion) 영역에 대한 오류를 보정한 disparity map을 생성하는데 초점을 둔다.

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A Study on the Regional Patterns of Income and Urban-Rural Disparity in China: Hypothesis Testing of Williamson and Amos (중국의 소득 및 도·농간 지역격차 패턴에 관한 연구 : Williamson과 Amos의 가설검증)

  • Kim, Jong-Sup;Jang, Hun;Zhang, Rui
    • International Area Studies Review
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    • v.17 no.4
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    • pp.67-88
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    • 2013
  • The purpose of this study empirically examines the pattern of regional disparities on the level of development in China's eastern, central, western and northeast regions for the period 1978-2012. To do this, it test Williamson's inverted-U hypothesis and Amos' augmented inverted-U hypothesis, focusing on polarization, polarization reversal, and spatial restructuring. Results of study are as follows: In the absolute economic disparity(AED) models of per capita income within a region, the Williamson's inverted-U hypothesis was supported in the eastern region, central region and inter-region model. The central region and the western region supports Williamson's hypothesis in the case of the relative economic disparity(RED). On the other hand, The inter-region model and the western region supports Amos' augmented inverted-U hypothesis in model of per capita income. In the urban-rural income economic disparity model, the inter-region model of AED and the central region of RED supports Amos' augmented inverted-U hypothesis. But the Williamson's inverted-U hypothesis was supported in the inter-region model and the western region in RED.

Comparative Analysis of Cost Aggregation Algorithms in Stereo Vision (스테레오 비전에서 비용 축적 알고리즘의 비교 분석)

  • Lee, Yong-Hwan;Kim, Youngseop
    • Journal of the Semiconductor & Display Technology
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    • v.15 no.1
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    • pp.47-51
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    • 2016
  • Human visual system infers 3D vision through stereo disparity in the stereoscopic images, and stereo visioning are recently being used in consumer electronics which has resulted in much research in the application field. Basically, stereo vision system consists of four processes, which are cost computation, cost aggregation, disparity calculation, and disparity refinement. In this paper, we present and evaluate the existing various methods, focusing on cost aggregation for stereo vision system to comparatively analyze the performance of their algorithms for a given set of resources. Experiments show that Normalized Cross Correlation and Zero-Mean Normalized Cross Correlation provide higher accuracy, however they are computationally heavy for embedded system in the real time systems. Sum of Absolute Difference and Sum of Squared Difference are more suitable selection for embedded system, but they should be required on improvement to apply to the real world system.

Multi-view video coding using efficient disparity vector prediction (다시점 동영상에서의 효율적인 변이 벡터 압축 기법)

  • Kim, Yong-Tae;Sohn, Kwang-Hoon
    • Journal of Broadcast Engineering
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    • v.10 no.4 s.29
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    • pp.621-631
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    • 2005
  • To enhance the performance of multi-view sequence CODEC, an efficient disparity vector coding method fur multiview sequences is proposed herein. For higher coding efficiency, we encode the differential vectors acquired by subtracting the original vectors from the predicted ones. To enhance the performance of disparity vector coding, it is essential to predict the disparity vectors accurately. The prediction by this proposed method utilizes the correlation among the multiview images, while conventional methods exploit the correlation among the causal blocks. Experiments were performed fur three different 5 view sequences. We were able to confirm that the proposed method predicts disparity vectors accurately by comparing the entropy and the mean absolute values for differential vectors with conventional methods. Its performance is superior to vector coding methods used in MPEG-4 which uses only a spatial correlation. The proposed method increases the coding efficiency by a factor of $30{\~}45\%$ while preserving image quality.

Measuring Socioeconomic Disparities in Cancer Incidence in Tehran, 2008

  • Rohani-Rasaf, Marzieh;Moradi-Lakeh, Maziar;Ramezani, Rashid;Asadi-Lari, Mohsen
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.6
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    • pp.2955-2960
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    • 2012
  • Background: Health disparities exist among and within countries, while developing and low income countries suffer more. The aim of this study was to quantify cancer disparities with regard to socioeconomic position (SEP) in 22 districts of Tehran, Iran. Method: According to the national cancer registry, 7599 new cancer cases were recorded within 22 districts of Tehran in 2008. Based on combined data from census and a population-based health equity study (Urban HEART), socioeconomic position (SEP) was calculated for each district. Index of disparity, absolute and relative concentration indices (ACI & RCI) were used for measuring disparities in cancer incidence. Results: The overall cancer age standardised rate (ASR) was 117.2 per 100,000 individuals (120.4 for men and 113.5 for women). Maximum ASR in both genders was seen in districts 6, 3, 1 and 2. Breast, colorectal, stomach, skin and prostate were the most common cancers. Districts with higher SEP had higher ASR (r=0.9, p<0.001). Positive ACI and RCI indicated that cancer cases accumulated in districts with high SEP. Female disparity was greater than for men in all measures. Breast, colorectal, prostate and bladder ASR ascended across SEP groups. Negative ACI and RCI in cervical and skin cancers in women indicate their aggregation in lower SEP groups. Breast cancer had the highest absolute disparities measure. Conclusion: This report provides an appropriate guide and new evidence on disparities across geographical, demographic and particular SEP groups. Higher ASR in specific districts warrants further research to investigate the background predisposing factors.

Disparity of Human Capital across Regions: the Impact of Aging (인적자본의 지역간 불평등: 고령화의 영향)

  • Kim, Woo-Yung
    • Journal of the Korean Geographical Society
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    • v.49 no.5
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    • pp.747-760
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    • 2014
  • This study presents the extent of disparity of human capital across regions, its trend, and the impact of aging on it, using Korean census data of years 1985, 1995, and 2005. Main results are as follows. First, the absolute level of human capital in cities and districts have increased, but the relative positions of those regions have not changed over time. Second, the proportion of college graduated tends to increase as the size of cities increases. Third, following Berry and Glaeser(2005), the increase in the proportion of college graduated is regressed on the initial proportion and the estimates indicate that the disparity of human capital across regions has increased over time. Fourth, the proportion of aging population is shown to have a negative relationship with the proportion of college graduated. Finally, using a counter-factual scenario that there were no differences in proportions of aging population across regions, it is shown that the disparity of human capital across regions could be reduced substantially.

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A Convergent Approach to Gain a Better Understanding of Alzheimer's Disease: Stereoscopic Vision (융복합적 접근을 통한 알츠하이머형 치매의 이해 증진 : 양안 지각)

  • Kim, Nam-Gyoon;Lee, Ho-Won
    • Journal of the Korea Convergence Society
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    • v.10 no.5
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    • pp.103-110
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    • 2019
  • The present study investigated the effects of AD on stereoscopic vision. Sixty participants (20 AD patients, 20 mild cognitive impairment patients, 20 healthy elderly controls) participated in the study. Two cubes, one on the left and the other on the right of the center of the monitor, appeared at varying distances from the observer with their relative distances controlled in two disparity conditions (absolute vs relative disparity) combined with two disparity directions (crossed vs uncrossed disparity). Participants identified the object that appeared closer to them. Results demonstrated comparable performance with all three groups performing accurately, suggesting that the effect of AD on stereopsis is negligible. Discussion focused on brain pathology affected by AD involving high level visual processing.

Robust Depth Map Estimation of Anaglyph Images (애너글리프 영상을 이용한 깊이 영상 취득 기법)

  • Williem, Williem;Park, In Kyu
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2014.06a
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    • pp.133-134
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    • 2014
  • Conventional stereo matching algorithms fail when they deal with anaglyph image as its input because anaglyph image does not have similar intensity on both view images. To ameliorate such problems, we propose a robust method to obtain accurate disparity maps. The novel Absolute Adaptive Normalized Cross Correlation (AANCC) for anaglyph data cost is introduced in this paper. Then, it is followed by occlusion detection and segmentation-based plane fitting to achieve accurate depth map acquisition. Experimental results confirm that the proposed anaglyph data cost is robust and gives accurate disparity maps.

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