• Journal of Biosystems Engineering
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• 제23권4호
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• pp.381-390
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• 1998

An algorithm to extract the 3-D geometric information of a static object was developed using a set of 2-D computer vision system and a laser structured lighting device. As a structured light pattern, multi-parallel lines were used in the study. The proposed algorithm was composed of three stages. The camera calibration, which determined a coordinate transformation between the image plane and the real 3-D world, was performed using known 6 pairs of points at the first stage. Then, utilizing the shifting phenomena of the projected laser beam on an object, the height of the object was computed at the second stage. Finally, using the height information of the 2-D image point, the corresponding 3-D information was computed using results of the camera calibration. For arbitrary geometric objects, the maximum error of the extracted 3-D feature using the proposed algorithm was less than 1~2mm. The results showed that the proposed algorithm was accurate for 3-D geometric feature detection of an object.

• 제어로봇시스템학회논문지
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• 제22권3호
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• pp.186-191
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• 2016

This paper addresses the development of 3D data acquisition system (3D scanner) based laser structured-light image. The 3D scanner consists of a stripe laser generator, a conventional camera, and a rotation table. The stripe laser onto an object has distortion according to 3D shape of an object. By analyzing the distortion of the laser stripe in a camera image, the scanner obtains a group of 3D point data of the object. A simple semiconductor stripe laser diode is adopted instead of an expensive LCD projector for complex structured-light pattern. The camera has an optical filter to remove illumination noise and improve the performance of the distance measurement. Experimental results show the 3D data acquisition performance of the scanner with less than 0.2mm measurement error in 2 minutes. It is possible to reconstruct a 3D shape of an object and to reproduce the object by a commercially available 3D printer.

• Current Optics and Photonics
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• 제2권6호
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• pp.554-562
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• 2018

This study presents a color 3D scanner based on the laser structured-light imaging method that can simultaneously acquire 3D shape data and color of a target object using a single camera. The 3D data acquisition of the scanner is based on the structured-light imaging method, and the color data is obtained from a natural color image. Because both the laser image and the color image are acquired by the same camera, it is efficient to obtain the 3D data and the color data of a pixel by avoiding the complicated correspondence algorithm. In addition to the 3D data, the color data is helpful for enhancing the realism of an object model. The proposed scanner consists of two line lasers, a color camera, and a rotation table. The line lasers are deployed at either side of the camera to eliminate shadow areas of a target object. This study addresses the calibration methods for the parameters of the camera, the plane equations covered by the line lasers, and the center of the rotation table. Experimental results demonstrate the performance in terms of accurate color and 3D data acquisition in this study.

• Journal of Biosystems Engineering
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• 제24권2호
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• pp.159-166
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• 1999

A system to extract continuously the real 3-D geometric fearture information from 2-D image of an object, which is fed randomly via conveyor has been developed. Two sets of structured laser lightings were utilized. And the laser structured light projection image was acquired using the camera from the signal of the photo-sensor mounted on the conveyor. Camera coordinate calibration matrix was obtained, which transforms 2-D image coordinate information into 3-D world space coordinate using known 6 points. The maximum error after calibration showed 1.5 mm within the height range of 103mm. The correlation equation between the shift amount of the laser light and the height was generated. Height information estimated after correlation showed the maximum error of 0.4mm within the height range of 103mm. An interactive 3-D geometric feature extracting software was developed using Microsoft Visual C++ 4.0 under Windows system environment. Extracted 3-D geometric feature information was reconstructed into 3-D surface using MATLAB.

• 제어로봇시스템학회논문지
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• 제19권12호
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• pp.1089-1093
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• 2013

Depth extraction using the structured illumination method is popularly applied since it has the benefit of measuring the object without contact. With multiple spatial frequencies and phase-shifting techniques, it is possible to extract the depth of objects with large discontinuity. For applications such as 3D (Three Dimensional) displays, 3D information of the object is required and is useful if corresponding to each view of the display. For this purpose, hypercentric optics is appropriate to measure the depth information of an object with a large field of view that is applicable for a 3D display. By experiment, we present the feasibility for phase-shifting profilometry using hypercentric optics to obtain the depth information of an object with the field of view appropriate for a 3D display.

• 한국콘텐츠학회논문지
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• 제13권11호
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• pp.523-532
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• 2013

3차원 공간에서 물체를 재구성하기 위하여 제안된 기존 기법들은 여러 개의 카메라를 사용하거나 여러장의 사진을 촬영하여 물체를 재구성하기 때문에 특정한 하드웨어를 필요로 하거나 촬영 장소에 민감하고 시간이 오래 걸린다는 단점이 있다. 본 논문에서는 유비쿼터스 환경에서 구조광 기법을 이용하여 한 장의 사진의 정보로부터 3차원 물체를 재구성하는 방법을 제안한다. 구조광 기법 적용을 위한 칼라 패턴은 기존연구에서 제안된 것을 사용한다. 본 논문에서는 실제로 객체 재구성 성능에 매우 중요한 줄무늬 패턴 추출과 줄무늬 패턴 매칭에 다양한 영상 처리 기법들로 구성된 파이프라인을 새롭게 제안하고, 패턴 매칭을 위한 최적의 비용 함수를 제안한다. 제안 기법을 통하여 갤럭시 빔과 같은 초소형 프로젝터를 탑재한 스마트폰과 같은 유비쿼터스 혹은 모바일 환경에서 적은 계산 복잡도와 간단한 환경 설정으로 3차원 물체를 재구성하는 것이 가능하다.

• 한국멀티미디어학회논문지
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• 제10권3호
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• pp.381-390
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• 2007

웹 가상공간에서 3D 객체로 이루어져 있는 콘텐츠가 다양한 분야에서 활용되고 있지만, 현재까지는 주로 3D 가상공간을 둘러보거나 3D 객체를 시각화하는 것이 주요 목적이다. 한편, 분해 및 조립 등의 3D 객체의 조작과정을 정교하게 제어하고 또한 이러한 조작과정 자체를 기록하는 기술은 아직 초보적인 수준으로서 현재 조작한 결과만을 기록할 수 있는 정도이다. 따라서, 본 연구에서는 3D 객체로 이루어진 구조물에 대하여 조작과정을 의미있게 기록하고 재생할 수 있는 표현기법을 연구하였다. XML 또는 VRML로 표현된 3D 구조물을 구성하는 객체간의 구조 및 관계를 분석하여 객체의 조작과 조작과정 기록에 활용하였다. 기존의 일방적인 조작결과의 기록에서 벗어나서 사용자가 선택적으로 조작과정을 기록하고 저장할 수 있는 XML 기반의 조작과정 어노테이션 기법을 연구하였다. 제시된 어노테이션 기법은 선택적인 기록이 가능할 뿐 아니라 선택적인 재생이 가능하여 3D 구조물의 다양한 활용을 가능하게 해준다.

• 한국정보통신학회논문지
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• 제8권5호
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• pp.1074-1079
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• 2004

지금까지 3차원 정보를 얻기 위하여 CCD카메라, 레이저, 구조화된 격자 발생기 등과 같은 여러 센서들이 사용되어져 왔지만 대부분의 캘리브레이션 알고리즘들은 많은 메모리와 실험 시간을 필요로 하기 때문에 비효율적이었다. 본 논문에서는 실세계 상의 3차원 정보를 얻기 위한 삼각법을 기반으로한 구조화된 격자 캘리브레이션 알고리즘이 소개된다. CCD카메라와 수평으로 설치된 구조화된 격자 패턴 생성기로부터 생성된 빔들이 캘리브레이션 면에 사영된다. CCD 카메라는 대상물과 사영된 빔이 교차한 평면을 측정한다. 그리고 3차원 데이터는 측정된 값과 캘리브레이션 데이터를 이용하여 계산된다. 본 논문에서 제안한 방범은 3차원 정보를 간단한 삼각법으로 획득하였기 때문에 효율적인 측정시간과 메모리 절약의 이점을 가지고 있다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2022년도 추계학술발표대회
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• pp.288-289
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• 2022

In this paper, we propose a method of obtaining high density geometric information using multi-view structured light. Reconstruction error due to the difference in resolution between the projector and the camera occurs when reconstruction a 3D shape from a structured light system to a single projector. This shows that the error in the point cloud in 3D is also the same when reconstruction the shape of the object. So we propose a high density method using multiple projectors to solve such a reconstruction error.

• 한국정밀공학회지
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• 제17권8호
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• pp.60-70
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• 2000

In this paper a 3D position measuring device that finds the 3D position of an arbitarily placed object using a camersa system is introduced. The camera system consists of three stepping motors and a CCD camera and a laser. The viewing direction of the camera is controlled by two stepping motors (pan and tilt motors) and the direction of a laser is also controlled by a stepping motors(laser motor). If an object in a remote place is selected from a live video image the x,y,z coordinates of the object with respect to the reference coordinate system can be obtained by calculating the distance from the camera to the object using a structured light scheme and by obtaining the orientation of the camera that is controlled by two stepping motors. The angles o f stepping motors are controlled by a SGI O2 workstation through a parallel port. The mathematical model of the camera and the distance measuring system are calibrated to calculate an accurate position of the object. This 3D position measuring device can be used to acquire information that is necessary to monitor a remote place.