• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.6_2
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• pp.635-643
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• 2007

As the availability of images from Airborne Digital Camera with high resolution is expanded, a lot of concern are in the production and update of digital map. This study presents the method of updating the digital map at the scale of 1/1,000 using images from Aerial Digital Camera. Geometric correction was completed using GPS surveying data. For digital mapping, digital photogrammetric system was utilized to digitize buildings and roads. The absolute positional accuracy was evaluated using GPS surveying data and the relative positional accuracy was evaluated using the digital map produced by analytical mapping. The absolute positional accuracy was as follows: RMSE in X and Y were ${\pm}0.172m\;and\;{\pm}0.127m$, and average distance error was 0.208m. The relative positional accuracy was as follows: RMSE in X and Y were ${\pm}0.238m\;and\;{\pm}0.281m$, and average distance error was 0.337m. Accuracies of updating digital map using images from airborne Digital Camera were within allowable error established by NGII. Consequently, images from airborne Digital Camera can be used in various fields including the production of the national basic map and the GIS of local government.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.150-161
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• 2013

This paper presents a new system which produces high resolution 3D contents by capturing multiview images of an object using multiple cameras, and estimating geometric and texture information of the object from the captured images. Even though a variety of multiview image-based 3D reconstruction systems have been proposed, it was difficult to generate high resolution 3D contents because multiview image-based 3D reconstruction requires a large amount of memory and computation. In order to reduce computational complexity and memory size for 3D reconstruction, the proposed system predetermines the regions in input images where an object can exist to extract object boundaries fast. And for fast computation of a visual hull, the system represents silhouettes and 3D-2D projection/back-projection relations by chain codes and 1D homographies, respectively. The geometric data of the reconstructed object is compactly represented by a 3D segment-based data format which is called DoCube, and the 3D object is finally reconstructed after 3D mesh generation and texture mapping are performed. Experimental results show that the proposed system produces 3D object contents of $800{\times}800{\times}800$ resolution with a rate of 2.2 seconds per frame.

• Korean Journal of Remote Sensing
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• v.31 no.5
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• pp.421-432
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• 2015

There are significant differences in geometric property and stereo model accuracy between single-sensor stereo that uses two images taken by stereo acquisition mechanism within identical sensor and dual-sensor stereo that randomly combines two images taken from two different sensors. This paper compares the two types of stereo pairs thoroughly. For experiment, two single-sensor stereo pairs and four dual-sensor stereo pairs were constituted using SPOT-5 stereo and KOMPSAT-2 stereo covering same area. While the two single-sensor stereos have stable geometry, the dual-sensor stereos produced two stable and two unstable geometries. In particular, the unstable geometry led to a decrease in stereo model accuracy of the dual-sensor stereos. The two types of stereo pairs were also compared under the stable geometry. Overall, single-sensor stereos performed better than dual-sensor stereos for vertical mapping, but dual-sensor stereos was more accurate for horizontal mapping. This paper has revealed the differences of two types of stereos with their geometric properties and positioning accuracies, suggesting important considerations for handling satellite stereo images, particularly for dual-satellite stereo images.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.6
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• pp.687-695
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• 2011

Many internet portals provide maps with spatial information services. Recently, various images including aerial, satellite, street view, and photo-realistic 3D city models are provided as well as maps. This study suggested a method for geometric correction of the panoramic aerial images in the internet portal and 3D building modeling using information which is available in the internet. The key of this study is to obtain all necessary data easily from internet without restrictions. Practically, the ground control coordinates could be available from geo-referenced internet maps, and stereo pairs of the aerial images and close-range photographs for photo-realistic object modeling are provided by the internet service. However, the ground control points are not suitable for accurate mapping. RMSE of the plotting was about 9 meters and reduced upto 4 meters after coordinate transformation. The proposed methods would be applicable to various applications of photo-realistic object modeling which do not require high accuracy.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.2
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• pp.181-188
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• 2012

The most recent, Digital photogrammetric camera, Airborne LiDAR and GPS/INS same sensors are used to acquire spatial information of various kinds in the field of aerial survey. In addition, Direct Georeferencing technology has been widely utilized with digital photogrammetric camera and GPS/INS. However, the sensor Calibration to be performed according to the combination of various sensors is followed by problems. Most of all, boresight calibration of integrated sensors is a critical element in the mapping process when using direct georeferencing or using the GPS/INS aerotriangulation. The establishment of a national test-bed in Sejong-si for aerial sensor calibration is absolutely necessary to solve this problem. And accurate calibration with used to integration of GPS/INS by aerotriangulation of aerial imagery was necessary for determination of system parameters, evaluation of systematic errors. Also, an investigation of efficient method for Direct georeferencing to determine the exterior orientation parameters and assessment of geometric accuracy of integrated sensors are performed.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.3
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• pp.353-360
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• 2012

This paper describes a SLAM method which estimates landmark locations and robot pose simultaneously. The particle filter can deal with nonlinearity of robot motion as well as the non Gaussian property of robot motion uncertainty and sensor error. The state to be estimated includes the locations of landmarks in addition to the robot pose. In the experiment, four beacons which transmit ultrasonic signal are used as landmarks. The robot receives the ultrasonic signals from the beacons and detects the distance to them. The method uses rang scanning sensor to build geometric feature of the environment. Since robot location and heading are estimated by the particle filter, the scanned range data can be converted to the geometric map. The performance of the method is compared with that of the deadreckoning and trilateration.

• Journal of the Korea Society of Computer and Information
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• v.27 no.5
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• pp.85-92
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• 2022

In this paper, we propose a technique that can express low-resolution hair and fur simulations in high-resolution without noise using ConvNet and geometric images of strands in the form of lines. Pairs between low-resolution and high-resolution data can be obtained through physics-based simulation, and a low-resolution-high-resolution data pair is established using the obtained data. The data used for training is used by converting the position of the hair strands into a geometric image. The hair and fur network proposed in this paper is used for an image synthesizer that upscales a low-resolution image to a high-resolution image. If the high-resolution geometry image obtained as a result of the test is converted back to high-resolution hair, it is possible to express the elastic movement of hair, which is difficult to express with a single mapping function. As for the performance of the synthesis result, it showed faster performance than the traditional physics-based simulation, and it can be easily executed without knowing complex numerical analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2D
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• pp.311-316
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• 2006

Despite geospatial information systems are widely used in many different fields as a powerful tool for spatial analysis and decision-making, their capabilities to handle realistic 3-D urban environment are very limited. The objective of this work is to integrate the recent developments in 3-D modeling and visualization into GIS to enhance its 3-D capabilities. To achieve a photorealistic view, building models are collected from a pair of aerial stereo images. Roof and wall textures are respectively obtained from ortho-rectified aerial image and ground photography. This study is implemented by using ArcGIS as the work platform and ArcObjects and Visual Basic as development tools. Presented in this paper are 3-D geometric modeling and its data structure, texture creation and its association with the geometric model. As the results, photorealistic views of Purdue University campus are created and rendered with ArcScene.

• Fashion & Textile Research Journal
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• v.6 no.1
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• pp.17-22
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• 2004

The purpose of this study was to obtain the basic element of patterns, which is the motif, from the existing art works and use it to create and simulate a variety of patterns to show the practical use of the computer. Natural dyed works of geometric shapes like squares and 1/4 of circles, each dyed with a different natural dyes, were produced and motifs were extracted. Then using the 4D box in Adobe Photoshop v.6.0, the developing pattern change and simulation effects when using different patterns and different repetition settings were examined. Observations were made as the motifs were replicated. Different patterns like a diagonal line, a square and a circle appeared. In order to find out the effects according to the changes, the motifs from work's square portions, circle centre, and the composition of eight motifs were extracted and used. The repeated patterns according to the extracted motifs simply showed that in the case of just repeating and arranging, square patterns appeared. By replicating and arranging, the motif and the allophone were matched and patterns with regular lines were formed, like a twill, pointed twill line. By setting the direction to Y and X in the repetition methodes, a typical half-drop arrangement or a brick pattern arrangement were formed according to 1/4, 2/4, 3/4, 1/3, or 2/3 in changes. Also the steepness of the slope changes quickly or in turn slowly as the rhombus shape appears. However in the case of a composed motif, an ogee pattern appeared. Lastly, by 3-D mapping patterns like a slant line, pointed twill patterns, diamond patterns, and the repeat patterns of a motif with a circle and a line combined, and a circle motif, an optical illusion could be observed.

• Journal of Broadcast Engineering
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• v.23 no.5
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• pp.622-627
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• 2018

In this paper, we introduce an integrated augmented reality system using a small camera and a projector. We extract three-dimensional information of an object with a small portable camera and a projector by using a structured light system. We develop the concept of the virtual camera to generalize the projection method so that the image can be projected at a desired position with only the mesh of the object to be projected without computing the mapping between specific point sets. Therefore, it is possible to project not only simple planes but also complex curved surfaces to desired positions without complicated geometric calculation. Based on a robot with a small camera and a projector, it will largely explain the projector-camera system calibration, the calculation of the position of the recognized object, and the image projection method using the virtual camera concept.