• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.1159-1181
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• 2016

This study introduces an image-based 2D-to-3D conversion system that provides significant stereoscopic visual effects for humans. The linear and atmospheric perspective cues that compensate each other are employed to estimate depth information. Rather than retrieving a precise depth value for pixels from the depth cues, a direction angle of the image is estimated and then the depth gradient, in accordance with the direction angle, is integrated with superpixels to obtain the depth map. However, stereoscopic effects of synthesized views obtained from this depth map are limited and dissatisfy viewers. To obtain impressive visual effects, the viewer's main focus is considered, and thus salient object detection is performed to explore the significance region for visual attention. Then, the depth map is refined by locally modifying the depth values within the significance region. The refinement process not only maintains global depth consistency by correcting non-uniform depth values but also enhances the visual stereoscopic effect. Experimental results show that in subjective evaluation, the subjectively evaluated degree of satisfaction with the proposed method is approximately 7% greater than both existing commercial conversion software and state-of-the-art approach.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.5
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• pp.431-438
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• 2017

The information management system for urban planning, urban management and related decision making is increasing an importance in recent years. Especially, the information about 3D buildings in urban area is necessary for urban management related precise location based service. However, it takes a lot of time, effort, and costs to produce 3D modeling data of buildings. These problems have been found in many studies, but the research to solve these problems is still necessary. In this study, we have tested an efficient 3D modeling method of building to solve these problems. SketchUp was used to test 3D modeling methods with OSM(OpenStreetMap) data. The other 3D modeling method using a digital map was tested. The 3D modeling of building data was efficient using PlaceMaker, which can use OSM data. In addition, modeling was possible through simple editing of the digital map and automatic building generation. The efficiency of the research results is presented by comparing with the traditional method based on the regulation and the stadard man power issued by Korean government. These two 3D modeling methods of building tested through the study can be used as basic data for related research and work. Additional studies should be conducted to improve the accuracy of the building model and determine how to obtain height data efficiently.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.123.1-123
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• 2001

For Autonomous navigation of the mobile robots, the robots' capability to recognize 3D environment is necessary. In this paper, an on-line 3D map building method for autonomous mobile robots is proposed. To get range data on the environment, we use an sensor system which is composed of a structured light and a CCD camera based on optimal triangulation. The structured laser is projected as a horizontal strip on the scene. The sensor system can rotate $\pm$ $30{\Circ}$ with a goniometer. Scanning the system, we get the laser strip image for the environments and update planes composing the environment by some image processing steps. From the laser strip on the captured image, we find a center point of each column, and make line segments through blobbing these center poings. Then, the planes of the environments are updated. These steps are done on-line in scanning phase. With the proposed method, we can efficiently get a 3D map about the structured environment.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.123.5-123
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• 2001

For autonomous navigation of the mobile robots, the robots' capability to recognize 3D environment is necessary. In this paper, an on-line 3D map building method for autonomous mobile robots is proposed. To get range data on the environment, we use a sensor system which is composed of a structured light and a CCD camera based on optimal triangulation. The structured laser is projected as a horizontal strip on the scene. The sensor system can rotate$\pm$30$^{\circ}$ with a goniometer. Scanning the system, we get the laser strip image for the environments and update planes composing the environment by some image processing steps. From the laser strip on the captured image, we find a center point of each column, and make line segments through blobbing these center points. Then, the planes of the environments are updated. These steps are done on-line in scanning phase. With the proposed method, we can efficiently get a 3D map about the structured environment.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.2
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• pp.155-162
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• 2009

In walking guide robot, a guide vehicle detects an obstacle distribution in the walking space using range sensors, and generates a 3D grid map to map the obstacle information and the tactile display. And the obstacle information is transferred to a blind pedestrian using tactile feedback. Based on the obstacle information a user plans a walking route and controls the guide vehicle. The algorithm for 3D detection of an obstacle distribution and the method of mapping the generated obstacle map and the tactile display device are proposed in this paper. The experiment for the 3D detection of an obstacle distribution using ultrasonic sensors is performed and estimated. The experimental system consisted of ultrasonic sensors and control system. In the experiment, the detection of fixed obstacles on the ground, the moving obstacle, and the detection of down-step are performed. The performance for the 3D detection of an obstacle distribution and space mapping is verified through the experiment.

• The Journal of Korea Robotics Society
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• v.16 no.3
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• pp.189-198
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• 2021

In this paper, we introduce the software/hardware system that can reliably calculate the distance from sensor to the model regardless of point cloud density. As the 3d point cloud map is widely adopted for SLAM and computer vision, the accuracy of point cloud map is of great importance. However, the 3D point cloud map obtained from Lidar may reveal different point cloud density depending on the choice of sensor, measurement distance and the object shape. Currently, when measuring map accuracy, high reflective bands are used to generate specific points in point cloud map where distances are measured manually. This manual process is time and labor consuming being highly affected by Lidar sparsity level. To overcome these problems, this paper presents a hardware design that leverage high intensity point from three planar surface. Furthermore, by calculating distance from sensor to the device, we verified that the automated method is much faster than the manual procedure and robust to sparsity by testing with RGB-D camera and Lidar. As will be shown, the system performance is not limited to indoor environment by progressing the experiment using Lidar sensor at outdoor environment.

• Spatial Information Research
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• v.15 no.2
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• pp.95-109
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• 2007

Recently people have been offered location based services on road networks. The navigation system, one of applications, serves to find the nearest gas station or guide divers to the shortest path based 2D map. However 3D map is more important media than 2D map to make sense friendly for the real. Although 3D map's data size is huge, portable devices' storage space is small. In this paper, we define continuous perspective queries to support 3D map to mobile user on road networks and propose this queries processing method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2799-2804
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• 2014

In this paper, we suggest three-dimensional information extraction map system using integral imaging technique. Integral imaging can record multiple elemental images with different perspectives using a 2D image acquisition device with lenslet array. Using these images, integral imaging can obtain 3D information and display 3D image. In this paper, the position difference between elemental images can be obtained using summation of absolute difference (SAD), and then 3D information can be extracted. Therefore, this technique can find the height information of 3D objects.

• Current Optics and Photonics
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• v.4 no.6
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• pp.545-550
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• 2020

We propose a hole-filling method to solve discontinuous depth representation and to reduce the visible seams and cracks that cause the limitation of the viewing angle of the three-dimensional (3D) image in the multilayer type 3D display system. The occlusion and the disocclusion regions between layers, such as the visible seams and cracks, are a major bottleneck of the multilayer type 3D display system to represent a volumetric 3D image by stacking multiple images. As a result, in the reconstructed 3D image, the visible seams and cracks appear as brighter overlapping and undesirable cut-off. In order to resolve the problems above, we applied the depth-fused effect to the sub-depth map generating algorithm and improve the viewing characteristics of the multilayer type 3D display. The experimental demonstrations are also provided to verify the proposed scheme.

• The KIPS Transactions:PartD
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• v.19D no.3
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• pp.229-236
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• 2012

The demand for map applications in both Web and mobile environments has been rapidly increased with the population of Web and smart phone usage. Web-based map applications are mostly developed on such environments as ArcGIS and MapServer and mobile map applications are developed on such API levels as Google Maps and Yahoo Maps. But many parts of map applications are still constructed by coding because these environments don't support high level of automation. Our MapAppGen that we have designed and implemented enhances the Web-based map application productivity by generating the map related modules that can be applied to the Drupal that is one of popular content management systems(CMS's). Comparing the applications that are constructed by the Drupal-supported GMap or NodeMap, the applications that are constructed by MapAppGen provide information on not only the interested geographical feature but also its related geographical features. MapAppGen uses Google Maps API and Drupal is a module-based system that supports the creation, composition and management of contents. We are now working on automatic generation of mobile map applications with MapAppGen.