• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2012.11a
• /
• pp.46-49
• /
• 2012

본 논문에서는 3차원 입체 비디오처리 기술의 최종목표인 디지털 홀로그램을 생성하는데 필요한 객체의 좌표와 색상정보가 들어있는 같은 시점과 해상도인 RGB 영상과 깊이 영상을 획득하여 가상 시점의 디지털 홀로그램을 생성하는 시스템을 제안한다. 먼저, 가시광선과 적외선의 파장을 이용하여 파장에 따라 투과율이 달라지는 콜드 미러를 사용하여 각각의 시점이 같은 다시점 RGB와 깊이 영상을 얻는다. 카메라 시스템이 갖는 다양한 렌즈 왜곡을 없애기 위한 보정 과정을 거친 후에 해상도가 서로 틀린 RGB 영상과 깊이 영상의 해상도를 같게 조절한다. 그 다음, DIBR(Depth Image Based Rendering) 알고리즘을 이용하여 원하는 가상 시점의 깊이 정보와 RGB 영상을 생성한다. 그리고 깊이 정보를 이용하여 디지털 홀로그램으로 구현할 객체만을 추출한다. 마지막으로 컴퓨터 생성 홀로그램 (computer-generated hologram, CGH) 알고리즘을 이용하여 추출한 가상 시점의 객체를 디지털 홀로그램으로 변환한다.

• Proceedings of the Optical Society of Korea Conference
• /
• 2001.02a
• /
• pp.84-85
• /
• 2001

광학장비의 결상성능은 회절변조전달 성능(diffraction MTF) 이나 Strehl ratio 로 표시할 수 있다. 광학 렌즈 또는 거울의 표면 형상오차 등에 기인한 광학성능 저하는 이론적으로 잘 알려져 있으며, 입사동에서의 위상변조를 통하여 초분해능 광학계를 개발할려는 연구도 활발히 진행되고 있다. 헬기에 장착되어 야간 표적 획득 시스템으로 사용되고 있는 전방관측 적외선 열상장치는 볼 내부에 장착되며, 적외선 통과창으로서 이용되는 Ge 윈도우를 통하여 외부 영상을 획득한다. (중략)

• Proceedings of the KAIS Fall Conference
• /
• 2010.05a
• /
• pp.142-145
• /
• 2010

본 논문에서는 적외선 조명을 이용한 밝은 동공 효과와 전형적인 외형을 기반으로 한 사물 인식 기술을 결합하여 외부 조명의 간섭으로 밝은 동공 효과가 나타나지 않는 경우에도 견실하게 눈을 검출하고 추적 할 수 있는 방법을 제안한다. 눈 검출과 추적을 위해 SVM과 평균 이동 추적방법을 사용하였고, 적외선 조명과 카메라를 포함한 영상 획득 장치를 구성하여 제안된 방법이 효율적으로 다양한 조명하에서 눈 검출과 추적을 할 수 있음을 보여 주었다.

• KIPS Transactions on Software and Data Engineering
• /
• v.7 no.10
• /
• pp.377-382
• /
• 2018

This study deals with internal state and tissue density analysis methods for red ginseng grade determination. For internal measurement of red ginseng, there have been various studies on nondestructive testing methods since the 1990s, It was difficult to grasp the most important inner hole and inside whites in the grading. So in this study, we developed a closed capturing device for infra-red illumination environment, and developed an internal measurement system that can detect the presence and diameter of inner hole and inside whites. Made devices consisted of infrared lights with a high transmission rate of red ginseng in 920 nanometer wave band, a infra-red camera and a Y axis actuator with a red ginseng automatically controlled focus on the camera. The proposed algorithm performs an auto-focus system on the Y-axis actuator to automatically adjust the sharp focus of the object according to the size and thickness. Then red ginseng is rotated $360^{\circ}$ at $1^{\circ}$ intervals and 360 total images are acquired, and reconstructed as a sinogram through Radon transform and Back-projection algorithm was performed to acquire internal images of red ginseng. As a result of the algorithm, it was possible to acquire internal cross-sectional image regardless of the thickness and shape of red ginseng. In the future, if more than 10,000 different shapes and sizes of red ginseng internal cross-sectional image are acquired and the classification criterion is applied, it can be used as a reliable automated ginseng grade automatic measurement method.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2016.11a
• /
• pp.140-141
• /
• 2016

기존의 사람 계수 측정 시스템은 적외선 빔이나 열 감지 영상 장치를 통해 측정하였다. 하지만 이와 같은 방법으로 측정하면 객체가 들어가거나 나가는 정보는 제공하지 않는다. 이에 본 논문은 고정된 카메라를 이용하여 각 사람의 피부색과 옷차림 등의 RGB 정보를 이용한 사람 계수 측정 기법을 제안한다. RGB카메라 영상을 통하여 객체의 RGB 히스토그램을 얻은 후 각 객체에 대해 Bhattacharyya metric을 통한 histogram similarity을 계산하여 객체 추적 및 분류를 통해 사람 계수 측정을 한다. 제안된 시스템은 C/C++을 기반으로 구현하여, 사람 계수 측정 성능을 평가하였다.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.22 no.4
• /
• pp.494-499
• /
• 2012

In this paper, a new method for detecting various objects that can be risks to safety navigation in sea environment is proposed. By analysing Infrared(IR) images obtained from various sea environments, we could find out that object regions include both horizontal and vertical direction edges while background regions of sea surface mainly include vertical direction edges. Therefore, we present an approach to detecting object regions considering horizontal and vertical edges. To this end, in the first step, image enhancement is performed by suppressing noises such as sea glint and complex clutters using a statistical filter. In the second step, a horizontal edge map and a vertical edge map are generated by 1-D Discrete Cosine Transform technique. Then, a combined map integrating the horizontal and the vertical edge maps is generated. In the third step, candidate object regions are detected by a adaptive thresholding method. Finally, exact object regions are extracted by eliminating background and clutter regions based on morphological operation.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.7
• /
• pp.693-701
• /
• 2010

In this paper, it is proposed that an attitude and position estimation algorithm based on a stereo camera system for a helmet tracker. Stereo camera system consists of two CCD camera, a helmet, infrared LEDs and a frame grabber. Fifteen infrared LEDs are feature points which are used to determine the attitude and position of the helmet. These features are arranged in triangle pattern with different distance on the helmet. Vision-based the attitude and position algorithm consists of feature segmentation, projective reconstruction, model indexing and attitude estimation. In this paper, the attitude estimation algorithm using UQ (Unit Quaternion) is proposed. The UQ guarantee that the rotation matrix is a unitary matrix. The performance of presented algorithm is verified by simulation and experiment.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.21 no.2
• /
• pp.260-267
• /
• 2011

This paper proposes a method for segmenting objects from the background in IR(Infrared) images based on GrabCut algorithm. The GrabCut algorithm needs the window encompassing the interesting known object. This procedure is processed by user. However, to apply it for object recognition problems in image sequences. the location of window should be determined automatically. For this, we adopted the Otsu' algorithm for segmenting the interesting but unknown objects in an image coarsely. After applying the Otsu' algorithm, the window is located automatically by blob analysis. The GrabCut algorithm needs the probability distributions of both the candidate object region and the background region surrounding closely the object for estimating the Gaussian mixture models(GMMs) of the object and the background. The probability distribution of the background is computed from the background window, which has the same number of pixels within the candidate object region. Experiments for various IR images show that the proposed method is proper to segment out the interesting object in IR image sequences. To evaluate performance of proposed segmentation method, we compare other segmentation methods.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.46 no.7
• /
• pp.557-566
• /
• 2018

In this paper, a vision-based relative navigation system is addressed for autonomous aerial refueling. In the air-to-air refueling, it is assumed that the tanker has the drogue, and the receiver has the probe. To obtain the relative information from the drogue, a vision-based imaging technology by infra-red camera is applied. In this process, the relative information is obtained by using Gaussian Least Squares Differential Correction (GLSDC), and Levenberg-Marquadt(LM), where the drouge geometric information calculated through image processing is used. These two approaches proposed in this paper are analyzed through numerical simulations.

• Korean Journal of Optics and Photonics
• /
• v.28 no.4
• /
• pp.153-157
• /
• 2017

An infrared camera and laser common-path optical system is applied to DIRCM (directional infrared countermeasures), to increase boresighting accuracy and decrease weight. Thermal effects of a laser beam in a common-path optical system are analyzed and evaluated, to predict any degradation in image quality. A laser beam with high energy density is absorbed by and heats the optical components, and then the surface temperature of the optical components increases. The heated optical components of the common-path optical system decrease system transmittance, which can degrade image quality. For analysis, the assumed simulation condition is that the laser is incident for 10 seconds on the mirror (aluminum, silica glass, silicon) and lens (sapphire, zinc selenide, silicon, germanium) materials, and the surface temperature distribution of each material is calculated. The wavelength of the laser beam is $4{\mu}m$ and its output power is 3 W. According to the results of the calculations, the surface temperature of silica glass for the mirror material and sapphire for the lens material is higher than for other materials; the main reason for the temperature increase is the absorption coefficient and thermal conductivity of the material. Consequently, materials for the optical components with high thermal conductivity and low absorption coefficient can reduce the image-quality degradation due to laser-beam thermal effects in an infrared camera and laser common-path optical system.