• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.6
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• pp.1-7
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• 2011

The depth camera measures range information of the scene in real time using Time-of-Flight (TOF) technology. Measured depth data is then regularized and provided as a depth image. This depth image is utilized with the stereo or multi-view image to generate high-resolution depth map of the scene. However, it is required to correct noise and distortion of TOF depth image due to the technical limitation of the TOF depth camera. The corrected depth image is combined with the color image in various methods, and then we obtain the high-resolution depth of the scene. In this paper, we introduce the principal and various techniques of sensor fusion for high-quality depth generation that uses multiple camera with depth cameras.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.2
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• pp.91-98
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• 2010

This study proposes a monitoring system that effectively watches surroundings by cooperating the various sensor information including image information on a sensor network system. The monitoring system proposed in this paper is developed to watch certain intruders to the internal spaces through the interested region for exceptional time by installing cameras, PIR(Pyroelectric Infrared Ray) sensor and body detectors in such interested regions. Moreover the monitering system is implemented based on the SenWeaver plateform which is a integrated development tools for building wireless sensor network system. In the results of the test that was applied to a practically experimental environment by implementing some interfaces for the proposed system, it was considered that it is possible to watch surroundings effectively using the image information obtained from cameras and multiple sensor information acquisited from sensor nodes.

• Smart Media Journal
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• v.11 no.9
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• pp.75-80
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• 2022

Recently, research and development on immersive virtual reality(VR) technology to provide a realistic experience is being widely conducted. To provide realistic experience in immersive virtual reality for VR participants, virtual environments should consist of high-realistic environments using 3D reconstruction. In this paper, to acquire 3D information in real space using multiple cameras in the reconstruction process, we propose a novel method of optimal camera placement for accurate reconstruction to minimize distortion of 3D information. Through our approach in this paper, real 3D information can obtain with minimized errors during environment reconstruction, and it is possible to provide a more immersive experience with the created virtual environment.

• ETRI Journal
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• v.26 no.6
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• pp.597-604
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• 2004

In stereoscopic television, there is a trade-off between visual comfort and 3-dimensional (3D) impact with respect to the baseline-stretch of a 3DTV camera. It is necessary to adjust the baseline-stretch at an appropriate the distance depending on the contents of a scene if we want to obtain a subjectively optimal quality of an image. However, it is very hard to obtain a small baseline-stretch using commercially available cameras of broadcasting quality where the sizes of the lens and CCD module are large. In order to overcome this limitation, we attempt to freely control the baseline-stretch of a stereoscopic camera by synthesizing the virtual views at the desired location of interval between two cameras. This proposed technique is based on the stereo matching and view synthesis techniques. We first obtain a dense disparity map using a hierarchical stereo matching with the edge-adaptive multiple shifted windows. Then, we synthesize the virtual views using the disparity map. Simulation results with various stereoscopic images demonstrate the effectiveness of the proposed technique.

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.418-427
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• 2016

A smart parking management requires to track a vehicle in a indoor parking lot and to detect the place where the vehicle is parked. An advanced parking system watches all space of the parking lot with CCTV cameras. We can use these cameras for vehicles tracking and detection. In order to cover a wide area with a camera, a fisheye lens is used. In this case the shape and size of an moving vehicle vary much with distance and angle to the camera. This makes vehicle detection and tracking difficult. In addition to the fisheye lens, the vehicle headlights also makes vehicle detection and tracking difficult. This paper describes a method of realtime vehicle detection and tracking robust to the harsh situation described above. In each image frame, we update the region of a vehicle and estimate the vehicle movement. First we approximate the shape of a car with a quadrangle and estimate the four sides of the car using multiple histograms of oriented gradient. Second we create a template by applying a distance transform to the car region and estimate the motion of the car with a template matching method.

• Transactions of Materials Processing
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• v.18 no.8
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• pp.633-639
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• 2009

Remarkable progress had been made in both technology and production of optical elements including aspheric lens. In the past, precision optical glass lenses were produced through multiple processes such as grinding and polishing, but mass production of aspheric lenses requiring high accuracy and having complex profile was rather difficult. Against such a background, the high-precision optical GMP process was developed with an eye on mass production of precision optical glass pasts by molding press. This GMP process can produce with precision and good repeatability special form lenses such as for cameras, video cameras, aspheric lenses for optical items. In this study, Design Of Experiment(Taguchi method) was adopted to find a tendency of molding conditions that influence formability. Three main factors for molding conditions were selected based on pressure at pressing stage and temperature, pressure at cooling stage. Also, the DOE was carried out and the interference patterns were measured to evaluate the formability of GMP process. From the results, it was found that the cooling pressure is the most sensitive parameter for progressive GMP process.

• Advances in robotics research
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• v.1 no.1
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• pp.81-99
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• 2014

This paper contributes towards the development of a computer vision system for telemonitoring of industrial articulated robotic arms. The system aims to provide precision real time measurements of the joint angles by employing low cost cameras and visual markers on the body of the robot. To achieve this, a mathematical model that connects image features and joint angles was developed covering rotation of a single joint whose axis is parallel to the visual projection plane. The feature that is examined during image processing is the varying area of given circular target placed on the body of the robot, as registered by the camera during rotation of the arm. In order to distinguish between rotation directions four targets were used placed every $90^{\circ}$ and observed by two cameras at suitable angular distances. The results were deemed acceptable considering camera cost and lighting conditions of the workspace. A computational error analysis explored how deviations from the ideal camera positions affect the measurements and led to appropriate correction. The method is deemed to be extensible to multiple joint motion of a known kinematic chain.

• International Journal of Computer Science & Network Security
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• v.23 no.1
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• pp.1-10
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• 2023

Open surface water body extraction is gaining popularity in recent years due to its versatile applications. Multiple techniques are used for water detection based on applications. Different applications of Radar as LADAR, Ground-penetrating, synthetic aperture, and sounding radars are used to detect water. Shortwave infrared, thermal, optical, and multi-spectral sensors are widely used to detect water bodies. A stereo camera is another way to detect water and different methods are applied to the images of stereo cameras such as deep learning, machine learning, polarization, color variations, and descriptors are used to segment water and no water areas. The Satellite is also used at a high level to get water imagery and the captured imagery is processed using various methods such as features extraction, thresholding, entropy-based, and machine learning to find water on the surface. In this paper, we have summarized all the available methods to detect water areas. The main focus of this survey is on water detection especially in small patches or in small areas. The second aim of this survey is to detect water hazards for unmanned vehicles and off-sure navigation.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.01a
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• pp.223-225
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• 2013

본 논문에서는 카메라가 여러 개 존재하는 다중의 카메라 환경에서 주변의 환경에 최적으로 적합한 카메라를 동적으로 선택하는 알고리즘을 제안한다. 제안된 알고리즘에서는 초기의 입력영상을 받아들인 후, 이 영상으로부터 주위의 환경을 가장 잘 표현할 수 있는 특징인 밝기와 텍스처 특징을 추출한다. 그리고 이전 단계에서 추출된 밝기와 텍스처 특징값들을 가장 잘 반영할 수 있는 카메라를 선택하는 규칙을 생성함으로써 주위 환경에 맞는 카메라를 자동으로 선택해 준다. 본 논문의 실험결과에서는 제안된 방법이 여러 가지 환경에서 잘 동작하며, 결과적으로 주위 환경에 적합한 카메라의 선택을 통해 보다 정확한 3차원의 정보를 추출함을 보여준다.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.553-556
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• 2005

We present a vision-based hand gesture recognition system for object manipulation in virtual space. Most conventional hand gesture recognition systems utilize a simpler method for hand detection such as background subtractions with assumed static observation conditions and those methods are not robust against camera motions, illumination changes, and so on. Therefore, we propose a statistical method to recognize and detect hand regions in images using geometrical structures. Also, Our hand tracking system employs multiple cameras to reduce occlusion problems and non-synchronous multiple observations enhance system scalability. Experimental results show the effectiveness of our method.