• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
• /
• pp.83-86
• /
• 2005

This paper presents a method for point-based 3D building reconstruction using LiDAR data and digital map. The proposed method consists of three processes: extraction of building roof points, identification of roof types, and 3D building reconstruction. After extracting points inside the polygon of building, the ground surface, wall and tree points among the extracted points are removed through the filtering process. The filtered points are then fitted into the flat plane using ODR(Orthogonal Distance Regression). If the fitting error is within the predefined threshold, the surface is classified as a flat roof. Otherwise, the surface is fitted and classified into a gable or arch roof through RMSE analysis. Based on the roof types identified in automated fashion, the 3D building reconstruction is performed. Experimental results showed that the proposed method classified successfully three different types of roof and that the fusion of LiDAR data and digital map could be a feasible method of modelling 3D building reconstruction.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2003년도 춘계학술발표논문집 (상)
• /
• pp.527-530
• /
• 2003

In this paper, we implemented the voxel coloring method to reconstruct 3D object from synthetic input Images. Then compare the result between using standard voxel coloring and using coarse-to-fine method. We compared using different voxel space site to see the difference of time processing and the result of 3D object. Photorealistic 3D object reconstruction is a challenging problem in computer graphics. Vexel coloring considered the reconstruction problem as a color reconstruction problem, instead of shape reconstruction problem. This method works by discretizing scene space into yokels, then traversed and colored those in special order. Also there is an extension of voxel coloring method far decreasing the amount of processing time called coarse-to-fine method. This. method works using low resolution instead of high resolution as input and after processing finish, apply some kind of search strategy.

• 한국정보과학회논문지:시스템및이론
• /
• 제32권4호
• /
• pp.168-176
• /
• 2005

본 논문에서는 모델 기반으로 한 장의 사진으로부터 중점 정보를 포함한 선분을 이용하여 물체를 3차원 재구성하는 방법을 제안한다. 미리 정의된 다면체를 원시기하모델로 사용하며 한 장의 영상으로부터 복원을 시도하였다. 미리 정의된 다면체 모델을 원시기하모델로 사용하며 사용자가 원시기하모델(primitive)의 각 대응점(correspondence point)을 사진에 매핑 시키는 것으로서 3차원 재구성이 수행된다. 기존의 모델기반 3차원 재구성은 카메라 파라미터들을 복원하거나 반복(iteration)을 통한 오차최소화 기법을 사용하였다. 하지만 본 논문은 원시기하모델에 포함되어 있는 선분들과 그 선분들의 중점 정보로부터 선분을 3차원 복원하며 복원된 선분들로부터 원시기하모델을 재구성하는 방법을 제안한다. 이러한 방법은 선분을 복원하는 단계에서 요구되는 최소한의 카메라 파라미터(focal length) 만으로 원시기하모델을 재구성 할 수 있다.

• 로봇학회논문지
• /
• 제1권2호
• /
• pp.180-187
• /
• 2006

This paper presents a new sensor system, CALOS, for motion estimation and 3D reconstruction. The 2D laser sensor provides accurate depth information of a plane, not the whole 3D structure. On the contrary, the CCD cameras provide the projected image of whole 3D scene, not the depth of the scene. To overcome the limitations, we combine these two types of sensors, the laser sensor and the CCD cameras. We develop a motion estimation scheme appropriate for this sensor system. In the proposed scheme, the motion between two frames is estimated by using three points among the scan data and their corresponding image points, and refined by non-linear optimization. We validate the accuracy of the proposed method by 3D reconstruction using real images. The results show that the proposed system can be a practical solution for motion estimation as well as for 3D reconstruction.

• 정보처리학회논문지B
• /
• 제17B권3호
• /
• pp.183-188
• /
• 2010

본 연구에서는 여러 이미지를 이용하여 사실적인 3차원 장면의 모델을 얻는 방법이 구현되었다. 이미지는 파라메터를 모르는 카메라를 이용하여 여러 위치에서 획득한 것을 사용하였다. 먼저 특징점 추출 및 추적 방법을 사용하여 모든 이미지에 대한 대응점들을 구하고 이 점들을 사용하여 사영복원을 구한다. 그 다음 사영 복원된 값에 여러 제약조건을 사용하여 유클리디언 복원을 하면 특징점들의 3차원 좌표값이 계산된다. 이 좌표값을 이용하여 삼각형 메쉬를 구한 후 이 면에 텍스처 맵핑을 하면 사실적인 복원이 완성된다. 전체 시스템은 C++언어로 구현하였으며, 사용자 인터페이스는 Qt 라이브러리로, 텍스처 맵핑과 모델 가시화 부분은 OpenGL 그래픽스 라이브러리로 구현하였다. 구현된 시스템의 효용성을 보이기 위해 모의 데이터와 실제 이미지 데이터를 이용하여 실험한 결과를 포함하였으며 만족할 만한 복원 결과를 얻을 수 있었다.

• Journal of information and communication convergence engineering
• /
• 제19권3호
• /
• pp.180-187
• /
• 2021

In this paper, we present a computational volumetric reconstruction method for three-dimensional (3D) photon counting imaging with enhanced visual quality when low-resolution elemental images are used under photon-starved conditions. In conventional photon counting imaging with low-resolution elemental images, it may be difficult to estimate the 3D scene correctly because of a lack of scene information. In addition, the reconstructed 3D images may be blurred because volumetric computational reconstruction has an averaging effect. In contrast, with our method, the pixels of the elemental image rearrangement technique and a Bayesian approach are used as the reconstruction and estimation methods, respectively. Therefore, our method can enhance the visual quality and estimation accuracy of the reconstructed 3D images because it does not have an averaging effect and uses prior information about the 3D scene. To validate our technique, we performed optical experiments and demonstrated the reconstruction results.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
• /
• pp.1393-1395
• /
• 2003

In this research, we presented a data integration, which integrates ultra high resolution images and complementary data for 3D building reconstruction. In our method, as the ultra high resolution image, Three Line Sensor (TLS) images are used in combination with 2D digital maps, DSMs and both of them. Reconstructed 3D buildings, correctness rate and the accuracy of results were presented. As a result, optimized combination scheme of data sets , sensors and methods was proposed.

• 대한두경부종양학회지
• /
• 제26권2호
• /
• pp.198-203
• /
• 2010

Objectives : Getting full information from axial CT images needs experiences and knowledge. Sagittal and coronal images could give more information but we have to draw 3-dimensional images in mind with above informations. With aid of 3D reconstruction softwares, CT data are converted to visible 3D images. We tried to compare medical photographs of 15 surgical specimens from neck tumors with 3D reconstructed images of same patients. Material and Methods : Fifteen patients with neck tumors treated surgically were recruited. Medical photograph of the surgical specimens were collected for comparison. 3D reconstruction of neck CT from same patients with aid of 3D-doctor software gave 3D images of neck masses. Width and height of tumors of each photos and images from the same cases were calculated and compared statistically. Visual similarities were rated between photos and 3D images. Results : No statatistical difference were found in size between medical photos and 3D images. Visual similarity score were higher between 2 groups of images. Conclusion : 3D reconstructed images of neck mass looked alike the real photographs of excised neck mass with similar calculated sizes. It could give us reliable visual information about the mass.

• Journal of Electrical Engineering and Technology
• /
• 제13권1호
• /
• pp.438-444
• /
• 2018

Structured light vision system has been widely used in 3D surface profiling. Usually, it is composed of a camera and a laser which projects a line on the target. Calibration is necessary to acquire 3D information using structured light stripe vision system. Conventional calibration algorithms have found the pose of the camera and the equation of the stripe plane of the laser under the same coordinate system of the camera. Therefore, the 3D reconstruction is only possible under the camera frame. In most cases, this is sufficient to fulfill given tasks. However, they require multiple images which are acquired under different poses for calibration. In this paper, we propose a calibration algorithm that could work by using just one shot. Also, proposed algorithm could give 3D reconstruction under both the camera and laser frame. This would be done by using newly designed calibration structure which has multiple vertical planes on the ground plane. The ability to have 3D reconstruction under both the camera and laser frame would give more flexibility for its applications. Also, proposed algorithm gives an improvement in the accuracy of 3D reconstruction.

• 국제학술발표논문집
• /
• The 6th International Conference on Construction Engineering and Project Management
• /
• pp.674-675
• /
• 2015

A 3D indoor model becomes an indiscernible component of BIM (Building Information Modeling) and GIS (Geographic Information System). However, a huge amount of time and human resources are inevitable for collecting spatial measurements and creating such a 3D indoor model. Also, a varied forms of 3D indoor models exist depending on their purpose of use. Thus, in this study, three different 3D indoor models are defined as 1) omnidirectional images, 2) a 3D realistic model, and 3) 3D indoor as-built model. A series of reconstruction methods is then introduced to construct each type of 3D indoor models: they are an omnidirectional image acquisition method, a hybrid surveying method, and a terrestrial LiDAR-based method. The reconstruction methods are applied to a large and complex atrium, and their 3D modeling results are compared and analyzed.