• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.156-157
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• 2010

최근 새로운 영상시장의 개척과 디지털 기술의 발전에 더불어 차세대 3D 입체영상기술에 대한 관심 및 수요가 증가함에 따라 높은 질의 입체영상 구현을 위한 연구들이 활발히 이루어지고 있다. 입체영상을 구현함에 있어 3D 입체 카메라 시스템의 기술이 중요한 요소로 작용되며, 특히 좌/우 영상 확보 및 카메라 동조, 결합시키는 특수 장비인 입체 카메라 리그 시스템 기술에 대한 연구 및 개발이 국내외에서 활발히 진행되고 있다 본 논문에서는 3D 입체영상 구현을 위한 카메라 리그 시스템의 원리 및 구조에 대해서 기술하고, 국내외 기술개발 동향을 살펴본다. 이에 높은 양질의 입체영상 구현을 위한 3D 입체 카메라 리그 시스템 기술의 개발 방향을 제시하고자 한다.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.28.2-28
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• 2001

Three dimensional shape measurement techniques are widely needed in industries for product quality monitoring and control. X-ray imaging method is a promising technology to achieve three-dimensional Information, both the surface and inner structure of an object, since it can overcome the limitations of conventional visual or optical methods such as an occlusion problem or surface reflection properties. In this paper, we propose three dimensional volume reconstruction method based on x-ray stereo imaging technology. Here, the stereo images of an object from two different views are taken by changing the object pose rather than moving imaging plane as in conventional stereo vision method. We propose a series of image processing techniques to extract the features efficiently from x-ray images, where the occluded features in case of normal camera vision could be found ...

• Journal of the Optical Society of Korea
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• v.12 no.4
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• pp.275-280
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• 2008

We propose a method generating elemental images for the integral imaging using 4-step phaseshifting digital holography. Phase shifting digital holography is a way recording the digital hologram by changing the phase of the reference beam and extracting the complex field of the object beam. Since all 3D information is captured by phase-shifting digital holography, the elemental images for any specifications of the lens array can be generated from single phase-shifting digital holography. In experiment, phase-shifting is achieved by rotating half- and quarter- wave plates and the resultant interference patterns are captured by a $3272{\times}2469$ pixel CCD camera with $27{\mu}m{\times}27{\mu}m$ pixel size.

• IEMEK Journal of Embedded Systems and Applications
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• v.16 no.5
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• pp.171-177
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• 2021

It is difficult to accurately extract features of pedestrian because the pedestrian is photographed at a crosswalk using a camera positioned higher than the pedestrian. In addition, it is more difficult to extract features when a part of the pedestrian's body is covered by an umbrella or parasol or when the pedestrian is holding an object. Representative methods to solve this problem include Object Detection, Instance Segmentation, and Pose Estimation. Among them, this study intends to use the Pose Estimation method. In particular, we intend to increase the recognition rate of pedestrians in crosswalks by maintaining the image resolution through HigherHRNet and applying the foot estimation technique. Finally, we show the superiority of the proposed method by applying and analyzing several data sets covered by body parts to the existing method and the proposed method.

• Journal of the Korean Society of Visualization
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• v.19 no.1
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• pp.57-61
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• 2021

In order to determine erythrocyte sedimentation rate (ESR) indicating acute phase inflammation, a Westergren method has been widely used because it is cheap and easy to be implemented. However, the Westergren method requires quite a long time for 1 hour. In this study, a gated recurrent unit (GRU) neural network was used to reduce measurement time of ESR evaluation. The sedimentation sequences of the erythrocytes were acquired by the camera and data processed through image processing were used as an input data into the neural network models. The performance of a proposed models was evaluated based on mean absolute error. The results show that GRU model provides best accurate prediction than others within 30 minutes.

• IEMEK Journal of Embedded Systems and Applications
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• v.13 no.6
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• pp.321-328
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• 2018

This paper presents an automatic target tracking flight system using a PID controller based on velocity command of a multirotor UAV. The automatic flight system includes marker based onboard target detection and an automatic velocity command generation replacing manual controller. A quad-rotor UAV is equipped with a camera and an image processing computer to detect the marker in real time and to estimate the relative distance from the target. The marker tracking system consists of PID controller and generates velocity command based on the relative distance. The generated velocity command is used as the input of the UAV's original flight controller. The operation of the proposed system was verified through actual flight tests using a marker on top of a moving vehicle and tracks it to successfully demonstrate its capability using a quad-rotor UAV.

• Journal of the Semiconductor & Display Technology
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• v.17 no.2
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• pp.41-46
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• 2018

This paper proposes a new method for the number recognition on dot matrix LED display. The proposed method uses morphological processing that dilates dots of numbers and connects the dots into strokes. The size of numbers is normalized using horizontal projection because the gaps of dots are different according to the size of numbers. The numbers are segmented by connected component analysis and finally, template matching method recognizes the segmented numbers. The proposed method is implemented using C language in Raspberry Pi system with a camera module for a real-time image processing. Experiments were conducted by using various dot matrix LED displays. The results show that the proposed method is successful for the number recognition on dot matrix LED display.

• Journal of Korea Multimedia Society
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• v.22 no.5
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• pp.580-587
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• 2019

In this paper, a plane detection method using depth information is proposed. 3-D characteristics of a pixel are defined as a direction and length of a normal vector whose is calculated from a plane consisting of a local region centered on the pixel. Image coordinates of each pixel are transformed to 3-D coordinates in order to obtain the local planes. Regions of each plane are detected by calculating similarity of the 3-D characteristics. The similarity of the characteristics consists of direction and distance similarities of normal vectors. If the similarity of the characteristics between two adjacent pixels is enough high, the two pixels are regarded as consisting of same plane. Simulation results show that the proposed method using the depth picture is more accurate for detecting plane areas than the conventional method.

• Journal of the Semiconductor & Display Technology
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• v.18 no.2
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• pp.67-72
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• 2019

This paper proposes a new method for the recognition of resistor color band using a color segmentation in a HSI color model. The proposed method firstly segments a resistor in a chromatic color as a ROI from a background. Secondly, the color bands of the resistor are segmented by vertical projection profile using both the intensity and the saturation differentiation and finally, it recognizes the colors of the segmented color bands using hue, saturation and intensity values. The final results are the value of the resistor and the names of the recognized color. The proposed method is implemented using C language in Raspberry Pi system with a camera module for a real-time image processing. Experiments were conducted by using various resistor images. The results show that the proposed method is successful for the recognition of resistor color band.

• The Journal of Korea Robotics Society
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• v.14 no.3
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• pp.157-162
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• 2019

The video game Tetris is one of most popular game and it is well known that its game rule can be modelled as MDP (Markov Decision Process). This paper presents a DQN (Deep Q-Network) based game agent for Tetris game. To this end, the state is defined as the captured image of the Tetris game board and the reward is designed as a function of cleared lines by the game agent. The action is defined as left, right, rotate, drop, and their finite number of combinations. In addition to this, PER (Prioritized Experience Replay) is employed in order to enhance learning performance. To train the network more than 500000 episodes are used. The game agent employs the trained network to make a decision. The performance of the developed algorithm is validated via not only simulation but also real Tetris robot agent which is made of a camera, two Arduinos, 4 servo motors, and artificial fingers by 3D printing.