• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.7A
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• pp.520-528
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• 2003

This paper proposes a method of implementing synthetic stereo and an acoustic echo cancellation algorithm for multiple participant conference system. Synthetic stereo is generated by HRTF and two loudspeakers. A robust adaptive algorithm for synthetic stereo echo cancellation is proposed to reduce the weight misalignment due to near-end speech signals and ambient noises. The proposed adaptive algorithm is modified version of SMAP algorithm and the coefficients of adaptive filter is updated with cross correlation of input and estimation error signal normalized with sum of the autocorrelation of input signal and the power of the estimation error signal multiplied with projection order. This is more robust to projection order and ambient noise than conventional SMAP. Computer simulation show that the proposed algorithm effectively attenuates synthetic stereo acoustic echo.

• ETRI Journal
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• v.37 no.4
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• pp.752-765
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• 2015

We propose a novel post-processing algorithm and its very-large-scale integration architecture that simultaneously uses the passive and active stereo vision information to improve the reliability of the three-dimensional disparity in a hybrid stereo vision system. The proposed architecture consists of four steps - left-right consistency checking, semi-2D hole filling, a tiny adaptive variance checking, and a 2D weighted median filter. The experimental results show that the error rate of the proposed algorithm (5.77%) is less than that of a raw disparity (10.12%) for a real-world camera image having a $1,280{\times}720$ resolution and maximum disparity of 256. Moreover, for the famous Middlebury stereo image sets, the proposed algorithm's error rate (8.30%) is also less than that of the raw disparity (13.7%). The proposed architecture is implemented on a single commercial field-programmable gate array using only 13.01% of slice resources, which achieves a rate of 60 fps for $1,280{\times}720$ stereo images with a disparity range of 256.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.425-427
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• 2004

Many of the problems by using the microscope are related to the fact that the eyes of the surgeon must be continually fixed to the microscope eyepieces. In this paper, we describe a development of the stereoscopic monitoring system of the stereo microscope for reduced eyestrain or operator fatigue about the long time observations of the microscope. The system consists of the stereoscopic camera part, the stereoscopic image processor device and the polarized light stereoscopic monitor. The left and right images obtained form the two CCD cameras are the same as the eyepiece images. By use of the image processor, the polarized light stereoscopic monitor displayed a real-time stereo microscope images.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1907-1910
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• 2003

This paper describes a method of stereo image composition for mixed reality without camera calibration or complicate tracking algorithm. The proposed system tracks the panel which has blob makers, and composes virtual objects naturally using the method of texture mapping which is often used in geological computer graphics mapping when we do mapping 2D computer graphic data or man-made 2D images. The proposed algorithm makes it possible for us to compose virtual data even in the case that the panel is bent. For composing 3D object, the system uses depth information obtained from stereo image so that we do not need cumbersome procedure of camera calibration.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.107-110
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• 2003

In this paper, we propose sharing 3D media between multisite using enhanced Access Grid (e-AG) which is a composition of 3D display and Access Grld (AG) Conventional AG and other collaborative systems have a limitation to share immersive 3D media Thus, proposed system supports sharing 3D media contents in a AG meeting section. Real object can be shared by acquiring stereo image with pre-calibrated stereo camera and by delivering, and virtual object can be shared by transmitting state information after downloading 3D model. And also, real video scene acquired by stereo camera and virtual object from 3D model can be displayed on the 3D display system of each node adaptively. The characteristics of proposed sharing method are sharing 3D media, displaying 3D media on a system adaptively, supporting real-time interaction. The proposed sharing method will be used remote lecture, remote collaboration with 3D media.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.157-160
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• 2008

A realization for moving object detecting and tracking system in two dimensional plane using stereo line CCDs and lighting source is presented in this paper. Instead of processing camera images directly, two line CCD sensor and input line image is used to measure two dimensional distance by comparing the brightness on line CCDs. The algorithms are used the moving object tracking and coordinate converting method. To ensure the effective detection of moving path, a detection algorithm to evaluate the reliability of each measured distance is developed. The realized system results are that the performance of moving object recognizing shows 5mm resolution and mean error is 1.89%, and enables to track a moving path of object per 100ms period.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.258-263
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• 2019

Some animals have special sensing functions in order to find foods, home and mates. Instead of passively sensing, they discharge signals and then extract necessary information from the response. More importantly, they utilize the gradients of the sensed signal in order to find the destination or objects. In this paper this special strategy is formulated mathematically, i.e., the perturbation and the correlation based gradient estimation is developed. A stereo sensor system using temperature sensors mounted on motors is developed for verification. The proposed method can estimate the gradient of the measured value accurately. Using this method, the direction in the maximum measured value can be estimated accurately, and the position of the heat source can be estimated from the intersection of the directions estimated from both sensors.

• Journal of Power System Engineering
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• v.19 no.2
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• pp.27-32
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• 2015

This paper describes a distance measurement system with high accuracy that utilizes a stereo-based camera and a pan-tilt unit for automatically maintaining the positional relationship between a vessel and a target on the side of a facility at a close range. The measurement system offers an advantage in that it can measure the distance to a target while tracking it. In order to improve the ability to control the position of a vessel between it and a target while maintaining the distance especially at a close range, the accuracy of the measurement system has to be improved. The accuracy of the distance measured by our system is increased with revisions of the conclusively generated data of distance measurement. We verified the accuracy of our system from an experiment, which generated results that had an accuracy of 30 mm for distances in the range between 2-8 m.

• The Journal of the Korea Contents Association
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• v.16 no.1
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• pp.515-520
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• 2016

Volumetric image system has many applications recently in education, 3D movie, medical images but these applications have several problems that need to be overcome. Volumetric display may process a amount of visual data and design the high efficient vision system for realtime display. In case of stereo system for volumetric display motion vectors, disparity vectors from the stereoscopic sequences and residual images with the reference images has been transmitted, and the stereoscopic sequences have been reconstructed at the receiver for volumetric display. So central issue for the design of efficient volumetric image system lies in selecting an appropriate stereo matching and robust vision system. In this paper, we proposed high efficient vision system, which design vision stage with rotating and moving horizontally, and match the successive stereo image efficiently. In experimental results with volumetric image system, the proposed method represents high efficiency with minimizing error and low computational load for volumetric display.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.887-890
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• 2002

In this paper, a new 3D robot vision system using the hierarchical opto-digital algorithm is proposed and implemented. From some experimental results with the 20 frames of the stereo input image pairs, the proposed system is found to be able to effectively extract the area where the target object is located from the stereo input image regardless of the background noises.