• Journal of the Korean Institute of Intelligent Systems
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• v.8 no.6
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• pp.85-90
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• 1998

The most important step image processing is stereo matching process. That is finding pixels of 3 dimensional pair in the left and right image. There are two matching methods. One is an area based approach and the other is a feature based approach. An area based approach needs much calculation time. In the other hand, we have the advantage of calculation time in the feature based approach, but can not obtain matched data for all pixels in the image. In recent years, fuzzy image processing methods are developed to manage vagueness and noise in image and ambiguous, inconsistent knowledge in recognition step. In this paper, we propose a fuzzy stereo matching algorithm. This method converts brightness data of image to fuzzy membership value and processes an area based approach method for stereo matching algorithm. We experiment with some stereo images to validate effectiveness of this algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6C
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• pp.848-856
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• 2004

In this paper, a fast stereo matching algorithm based on pixel-wise matching strategy, which can get a stable and accurate disparity map, is proposed. Since a stereo image pair has small differences each other and the differences between left and right images are just caused by horizontal shifts with some order, the matching using a large window will not be needed within a given search range. However, disparity results of conventional pixel-based matching methods are somewhat unstable and wrinkled, the principal direction of disparities is checked by the accumulated cost along a path on array with the dynamic programming method. Experimental results showed that the proposed method could remove almost all disparity noise and set a good quality disparity map in very short time.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.683-686
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• 2005

This study addresses a photogrammetric approach to generate Mars topographic products from mapping data of Mars Global Surveyor (MGS). High-resolution stereo images and laser altimetry data collected from the MGS mission are combined and processed to produce Digital Elevation Models (DEM) and orthoimages. First, altimeter data is registered to high resolution images and considerable registration offset (around 325 m) is discovered on high resolution stereo images. Altimetry data, exterior orientation elements of the camera and conjugate points are used for bundle adjustment to solve this mis-registration and detennine the ground coordinates. The mis-registration of altimetry data are effectively eliminated after the bundle adjustment. Using the adjusted exterior orientation the ground coordinates of conjugate points are detennined. A sufficient number of corresponding points collected through image matching and their precise 3-D ground coordinates are used to generate DEM and orthoimages. A posteriori standard deviations of ground points after bundle adjustment indicate the accuracy of OEM generated in this study. This paper addresses the photogrammetric procedure: the registration of altimetry data to stereo pair images, the bundle adjustment and the evaluation, and the generation of OEM and orthoimages.

• Journal of Broadcast Engineering
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• v.10 no.1 s.26
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• pp.68-76
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• 2005

We propose a new type of stereoscopic camera system with a zoom lens module to overcome the backlash for the stability of picture matching and the difficulty of zoom control. This system is designed to control a pair of zoom lens with a rotation lever. In this paper, we present the structural characteristics of our proposed system, and verify that there are no image mismatching at acquired stereo images and the zoom in$\cdot$out is easy to control. In our experiments, we achieve good results that a convergence control is very simple and distortion of images is decreased.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.3
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• pp.255-260
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• 2003

In this paper, we generate the 3D geometric sensor model of SPOT-5 HRG stereo images which are processed in Supermode and have 2.5m ground spatial resolution, and calculate the RPC(Rational Polynomial Coefficients) for acquisition of topographic information using the exterior orientation parameters which are determined in the 3D geometric sensor modelling process. It is shown that SPOT-5 images can be modelled with me 3.3m accuracy by the bundle adjustment method used to model the existing SPOT series. Considering the accuracy of RPC's results with rmse 0.03m accuracy, the RPC model can replace the sensor model, if we emphasize the simplification and the cost.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.325-330
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• 1998

The first Korean remote sensing satellite, Korea Multi-Purpose Satellite (KOMPSAT-1), is going to be launched in 1999. This will carry a 7m resolution Electro-Optical Camera (EOC) for earth observation. The primary mission of the KOMPSAT-1 is to acquire stereo imagery over the Korean peninsular for the generation of 1:25,000 cartographic maps. For this mission, research is being carried out to assess the possibilities of automated or semi-automated mapping of EOC data and to develop, if necessary, such enabling tools. This paper discusses the issue of automated DEM generation from EOC data and identifies some important aspects in developing a for DEM generation system from EOC data. This paper also presents the current status of the development work for such a system. The development work has focused on sensor modelling, stereo matching and DEM interpolation techniques. The performance of the system is shown with a SPOT stereo pair. A DEM generated from a commercial software is also presented for comparison. The paper concludes that the proposed system creates preferable results to the commercial software and suggests future developments for successful generation of DEM for EOC data.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.37.4-38
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• 2009

Rho et al.(2008) showed that the eccentricity parameter of a CME is an important indicator for forecasting CME geoeffectiveness. In this study we have tested a capability of the eccentricity parameter as an indicator of CME direction. For this work we considered 11 CMEs observed by both SOHO/LASCO and STEREO/SECCHI (2007-2008 from Temmer et al. 2009) coronagraphs. We have estimated earthward direction angles for these CMEs based on two different methods: (1) the eccentricity parameter from a single coronagraph SOHO/LASCO and (2) the triangulation technique using a pair of spacecrafts LASCO/STEREO-A and LASCO/STEREO-B. As a result, we have found that for 7 out of 11 CME events their direction angles are consistent with each other within $20^{\circ}$. This result demonstrates that the earthward direction based on the eccentricity parameter can be a good potential indicator for CME propagation direction.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.511-513
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• 1998

This paper describes a full color stereoscopic video display system using a LCD shutter. Human apprehends the world with a natural stereo vision. The left eye sees through a slightly different perspective from the right eye; proposed vision system combines two images into a single image that has stereo depth. That is, when the left image is on the screen, the left shutter opens and the right shutter closes - and vice versa. The LCD shutter channels the left image to the left eye, and the right image to the right eye. The brain then fuses the stereo pair into a single high-resolution, flicker-free 3D image. The designed vision system is a real-time system that shows stereoscopic images without the loss of image information from video cameras.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.8
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• pp.3965-3983
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• 2017

We propose a novel eye tracking method that can estimate 3D world coordinates using an infrared (IR) stereo camera for indoor and outdoor environments. This method first detects dark evidences such as eyes, eyebrows and mouths by fast multi-level thresholding. Among these evidences, eye pair evidences are detected by evidential reasoning and geometrical rules. For robust accuracy, two classifiers based on multiple layer perceptron (MLP) using gradient local binary patterns (GLBPs) verify whether the detected evidences are real eye pairs or not. Finally, the 3D world coordinates of detected eyes are calculated by region-based stereo matching. Compared with other eye detection methods, the proposed method can detect the eyes of people wearing sunglasses due to the use of the IR spectrum. Especially, when people are in dark environments such as driving at nighttime, driving in an indoor carpark, or passing through a tunnel, human eyes can be robustly detected because we use active IR illuminators. In the experimental results, it is shown that the proposed method can detect eye pairs with high performance in real-time under variable illumination conditions. Therefore, the proposed method can contribute to human-computer interactions (HCIs) and intelligent transportation systems (ITSs) applications such as gaze tracking, windshield head-up display and drowsiness detection.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.518-523
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• 2002

Nowadays the Rational Function Model (RFM), an abstract sensor model, is substituting physical sensor models for highly complicated imaging geometry. But RFM is algorithm to be required many Ground Control Points (GCP). In case of RFM of the third order, At least forty GCP are required far RFM generation. The purpose of this study is to research more efficient algorithm on GCP and accurate algorithm similar to RFM. The Polynomial Camera Model is relatively accurate and requires a little GCP in comparisons of RFM. This paper introduces how to generate Polynomial Camera Model and fundamental algorithms for construction of 3-D topographic data using the Polynomial Camera Model information in the Kompsat stereo pair and describes how to generate the 3-D ground coordinates by manual matching. Finally we tried to extract height information for the whole image area with the stereo matching technique based on the correlation.