• Title/Summary/Keyword: Pixel-Based Estimation

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Depth Map Correction Algorithm based on Segmentation in Multi-view Systems (다중시점 환경에서의 슈퍼픽셀 세그먼테이션 기반 깊이 영상 개선 알고리즘)

  • Jung, Woo-Kyung;Han, Jong-Ki
    • Journal of Broadcast Engineering
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    • v.25 no.6
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    • pp.954-964
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    • 2020
  • In immersive media, the most important factor that provides immersion is depth information. Therefore, it is essential to obtain high quality depth information in order to produce high quality immersive media. In this paper we propose an algorithm to improve depth map, considering the segmentation of images and the relationship between multiple views in multi-view systems. The proposed algorithm uses a super-pixel segmentation technique to divide the depth map of the reference view into several segments, and project each segment into adjacent view. Subsequently, the depth map of the adjacent view is improved using plane estimation using the information of the projected segment, and then reversed to the reference view. This process is repeated for several adjacent views to improve the reference depth map by updating the values of the improved adjacent views and the initial depth map of the reference view. Through simulation, the proposed algorithm is shown to surpass the conventional algorithm subjectively and objectively.

Boundary Depth Estimation Using Hough Transform and Focus Measure (허프 변환과 초점정보를 이용한 경계면 깊이 추정)

  • Kwon, Dae-Sun;Lee, Dae-Jong;Chun, Myung-Geun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.1
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    • pp.78-84
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    • 2015
  • Depth estimation is often required for robot vision, 3D modeling, and motion control. Previous method is based on the focus measures which are calculated for a series of image by a single camera at different distance between and object. This method, however, has disadvantage of taking a long time for calculating the focus measure since the mask operation is performed for every pixel in the image. In this paper, we estimates the depth by using the focus measure of the boundary pixels located between the objects in order to minimize the depth estimate time. To detect the boundary of an object consisting of a straight line and a circle, we use the Hough transform and estimate the depth by using the focus measure. We performed various experiments for PCB images and obtained more effective depth estimation results than previous ones.

A Study on Target Selection from Seeker Image of Aerial Vehicle in Sea Environment (해상 탐지 영상에서의 비행체 표적 선정에 관한 연구)

  • Kim, Ki-Bum;Baek, In-Hye;Kwon, Ki-Jeong
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.5
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    • pp.708-716
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    • 2017
  • We deal with the target selection in seeker-detection image through network, using the detection information from aerial vehicle and the target information from surveillance and reconnaissance system. Especially, we constrain the sea battle environment, where it is difficult to perform scene-matching rather than land. In this paper, we suggest the target selection algorithm based on the confidence estimation with respect to distance and size. In detail, we propose the generation method of reference point for distance evaluation, and we investigate the effect of pixel margin and target course for size evaluation. Finally, the proposed algorithm is simulated and analyzed through several scenarios.

Defect Detection algorithm of TFT-LCD Polarizing Film using the Probability Density Function based on Cluster Characteristic (TFT-LCD 영상에서 결함 군집도 특성 기반의 확률밀도함수를 이용한 결함 검출 알고리즘)

  • Gu, Eunhye;Park, Kil-Houm
    • Journal of Korea Multimedia Society
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    • v.19 no.3
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    • pp.633-641
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    • 2016
  • Automatic defect inspection system is composed of the step in the pre-processing, defect candidate detection, and classification. Polarizing films containing various defects should be minimized over-detection for classifying defect blobs. In this paper, we propose a defect detection algorithm using a skewness of histogram for minimizing over-detection. In order to detect up defects with similar to background pixel, we are used the characteristics of the local region. And the real defect pixels are distinguished from the noise using the probability density function. Experimental results demonstrated the minimized over-detection by utilizing the artificial images and real polarizing film images.

A Study on the Fast Block Matching Algorithm (고속 Block Matching 알고리즘에 관한 연구)

  • 이인홍;박래홍
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.24 no.4
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    • pp.667-674
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    • 1987
  • In this paper an effective block matching algorithm is proposed to find the motion vector. There are two approaches to the estimation of the motion vector in MCC (motion compensated coding), i.e., pel(pixel element) recursive algorithm and block matching algorithm. The search algorithm in this paper is based on the block matching method. The advantage of a proposed algorithm using integral projections is the reduction of the computation time. While the conventional block matching methods have to be computed in 2-dimensional arrays, the proposed algorithm using integral projections can be computed in 1-dimensional arrays. In comparison with conventional block matching methods, a computer simulation shows that though the prediction error increases 0.23 db, it is not detectable for human eyes and the average reduction ratio of computation time obtained from the proposed algorithm is about 3-4.

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East Half-Pixel Motion Estimation Based on SAD Curve Modeling (SAD 함수 모델링을 이용한 고속 반화소 추정 알고리즘)

  • 이윤구;최부림;나종범
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.1924-1927
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    • 2003
  • 많은 고속 정화소 움직임 추정 알고리즘이 개발됨에 따라, 최근에는 10개의 탐색점만으로 정화소 움직임벡터를 찾을 수 있게 되었다. 반면에, 반화소 움직임 추정에서는 정화소 움직임 벡터주변의 8 개의 반화소 탐색점을 검색해야 한다 그러므로 반화소 움직임 추정 알고리즘의 계산량을 줄일 필요성이 생기게 되었다 본 논문에서는 directional search 와 SAD 함수의 선형 모델링을 이용한 고속 반화소 움직임 추정 알고리즘을 제안한다 제안된 알고리즘은 PSNR 열화 없이 2.21 개의 탐색만으로도 움직임 벡터를 찾을 수 있게 해준다 특히, 조절 가능한 파라미터를 이용하면. 약간의 PSNR 감소와 함께 0.34개의 탐색만으로 움직임 벡터를 추정을 할 수 있게 해준다.

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Realization of automatic video tracker using ASIC (ASIC을 이용한 자동영상 추적기 구현)

  • 강재열;윤상로
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.8
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    • pp.1885-1896
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    • 1996
  • This paper describes the implementation of the AVT(Automatic video Tracker) using ASIC. The basic tracking algorithm is based on the spatio-temporal gradient method, and adaptive window sizing, track state decision algorithm were also realized. Newly developed ASIC performs recursive image filtering, extraction of spatio-temporal gradient/gradient functions of image in field rate. Using the FPGA/ASIC, the tracker was simply realized in one board type which can be easily applied to various image system. We conformed ASIC operation by computer simulation and tested the system in real tracking situations. From the result, the system can track the moving target which has a velocity of 2-3 pixel/field and a size of varying from 2 to 128 pixes. Also fast refresh rateof motion estimation(60Hz) improves the characteristics of servoing system which forms feedback loop with the tracker.

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Estimation of Real Boundary with Subpixel Accuracy in Digital Imagery (디지털 영상에서 부화소 정밀도의 실제 경계 추정)

  • Kim, Tae-Hyeon;Moon, Young-Shik;Han, Chang-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.8
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    • pp.16-22
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    • 1999
  • In this paper, an efficient algorithm for estimating real edge locations to subpixel values is described. Digital images are acquired by projection into image plane and sampling process. However, most of real edge locations are lost in this process, which causes low measurement accuracy. For accurate measurement, we propose an algorithm which estimates the real boundary between two adjacent pixels in digital imagery, with subpixel accuracy. We first define 1D edge operator based on the moment invariant. To extend it to 2D data, the edge orientation of each pixel is estimated by the LSE(Least Squares Error)line/circle fitting of a set of pixels around edge boundary. Then, using the pixels along the line perpendicular to the estimated edge orientation the real boundary is calculated with subpixel accuracy. Experimental results using real images show that the proposed method is robust in local noise, while maintaining low measurement error.

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Pixel-based disparity estimation for Intermediate View Reconstruction of Multi-view images (다시점 동영상의 중간시점영상 생성을 위한 화소 기반의 변이 예측 기법)

  • Choi, Mi-Nam;Baek, Yun-Ki;Kim, Dong-Wook;Yoo, Ji-Sang
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2006.11a
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    • pp.49-52
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    • 2006
  • 본 논문은 다시점 카메라로부터 획득된 다시점 영상을 이용하여, 영상내의 모든 화소에 대한 정확한 변이 정보를 획득하는 알고리듬을 제안한다. 제안한 방법은 정합창(measurement window)을 사용하는 화소기반 정합방법을 통해 정확한 변이 추정과 비용 함수 계산시 반복적인 계산을 줄임으로써 전체적인 수행 속도를 향상시킬 수 있다. 정확한 변이 정보를 획득하는데 있어서 가려진 영역이 많은 영향을 미친다. 또한 가려진 영역의 판단 및 처리는 2대의 카메라로는 한계가 있다. 따라서 본 논문에서는 평행식으로 구성된 5대 이상의 다시점 카메라로부터 획득된 다시점 영상을 사용함으로써 변이 정보의 신뢰도를 높이고, 가려진 영역을 처리할 수 있다. 또한 비용 함수 계산의 반복성을 이용하여 계산량을 줄임으로써 전체적인 수행시간을 줄인다. 이렇게 획득된 변이 정보는 다시점 영상의 중간시점영상 생성을 위해 사용된다.

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View synthesis in uncalibrated images (임의 카메라 구조에서의 영상 합성)

  • Kang, Ji-Hyun;Kim, Dong-Hyun;Sohn, Kwang-Hoon
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.437-438
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    • 2006
  • Virtual view synthesis is essential for 3DTV systems, which utilizes the motion parallax cue. In this paper, we propose a multi-step view synthesis algorithm to efficiently reconstruct an arbitrary view from limited number of known views of a 3D scene. We describe an efficient image rectification procedure which guarantees that an interpolation process produce valid views. This rectification method can deal with all possible camera motions. The idea consists of using a polar parameterization of the image around the epipole. Then, to generate intermediate views, we use an efficient dense disparity estimation algorithm considering features of stereo image pairs. Main concepts of the algorithm are based on the region dividing bidirectional pixel matching. The estimated disparities are used to synthesize intermediate view of stereo images. We use computer simulation to show the result of the proposed algorithm.

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