Seo Hyun Kim
Samsung
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Seo Hyun Kim.
Proceedings of SPIE | 2012
Hana Ku; Seo Hyun Kim; Hong Jin Kong; Jun Ho Lee
We introduce a design of an Offner imaging spectrograph with its performance and tolerancing results. It is a traditional Offner spectrograph employing two concave mirrors and one convex reflective grating for dispersing light in the SWIR band (900~1700 nm). The optical system uses 25um-pitch pixels for the detector and the goal spectral sampling is 3.2nm. Its performance is analyzed in terms of MTFs, spot diagrams, and distortions – keystone and smile. This design focuses on the yaw(beta-tilt) sensitivity of the tertiary mirror as the compensator hence is expected to act as a performance-improving breakthrough for the entire system as the inverse sensitivity confirms it is the most sensitive component. The procedure of the inverse sensitivity evaluation is explained, and then budgeting the tolerances for each element for the practical production is described.
Proceedings of SPIE | 2011
Ayoung Heo; Jai-Hoon Lee; Eun-Jin Choi; Won-Chul Choi; Seo Hyun Kim; Dong-Jo Park
In this paper, we propose a denoising method for hyperspectral images using a joint bilateral filter. The joint bilateral filter with the fused image of hyperspectral image bands is applied on the noisy image bands. This fused image is a single grayscale image that is obtained by the weighted summation of hyperspectral image bands. It retains the features and details of each hyperspectral image band. Therefore the joint bilateral filter with the fused image is powerful in reducing noise while preserving the characteristics of the individual spectral bands. We evaluated the performance of the proposed noise reduction method on hyperspectral imaging systems, which we developed for visible and near-infrared spectral regions. Experimental results show that the proposed method outperforms the conventional approaches, such as the basic bilateral filter.
Adaptive Optics and Applications III | 2004
Jun Ho Lee; H. S. Gho; J. Hyu; Young Cheol Lee; E. C. Kang; Seo Hyun Kim; S. N. Lee
We are performing a research on the application of an adaptive optics system to upgrade the beam quality of a laser. We consider the adaptive optics system to consist of a bimorph mirror, a Shack-Hartmann sensor and a control system. Since the laser beam can be circular, annulus or square/rectangle, we predicted the performance of a circular bimorph deformable for each different beam shapes. We selected a bimorph mirror of 120 mm clear aperture with 31 actuators as a design candidate. Firstly we found that the fitting ability of the bimorph mirror for a circular/annulus beam can significantly improve by limiting the correctable area to an annulus of 100mm outer diameter and 20mm inner diameter, which our square laser beam fits into. This study shows that the bimorph mirror, which might be considered as a modal controller, can compensate the square lower order aberrations with fitting abilities larger than 0.95 for tilt, defocus, coma and astigmatism, and 0.82 for spherical aberration. Finally we concluded that the circular bimorph mirror is perfectly okay for square laser beam compensating.
Review of Scientific Instruments | 2014
Seo Hyun Kim; Hong Jin Kong; Jong Ung Lee; Jun Ho Lee; Jai Hoon Lee
A method to obtain an aberration-corrected Offner spectrometer without ray obstruction is proposed. A new, more efficient spectrometer optics design is suggested in order to increase its spectral resolution. The derivation of a new ring equation to eliminate ray obstruction is based on geometrical analysis of the ring fields for various numerical apertures. The analytical design applying this equation was demonstrated using the optical design software Code V in order to manufacture a spectrometer working in wavelengths of 900-1700 nm. The simulation results show that the new concept offers an analytical initial design taking the least time of calculation. The simulated spectrometer exhibited a modulation transfer function over 80% at Nyquist frequency, root-mean-square spot diameters under 8.6 μm, and a spectral resolution of 3.2 nm. The final design and its realization of a high resolution Offner spectrometer was demonstrated based on the simulation result. The equation and analytical design procedure shown here can be applied to most Offner systems regardless of the wavelength range.
Proceedings of SPIE | 2011
Jai-Hoon Lee; Ayoung Heo; Won-Chul Choi; Seo Hyun Kim; Dong-Jo Park
This paper presents an extended bilateral filter with spectral angles and a visualization scheme for hyperspectral image data. The conventional bilateral filter used to be implemented using a position vector and a luminance value at each pixel in the scene. Since hyperspectral image data can provide a spectrum vector that has hundreds of bands at each pixel, we propose an extended bilateral filter using spectral angles. The proposed bilateral filter can be used for extracting and preserving the spectrum edges of the hyperspectral image. A visualization scheme for hyperspectral images exploiting the proposed bilateral filter has been also proposed. When objects that have the similar tristimulus intensity but different spectrums are mixed, they can be separated through the proposed visualization scheme. The resulting images show that the proposed scheme facilitates anomaly detection in the hyperspectral scenes.
Archive | 2012
Young Zo Yoo; Seo Hyun Kim; Junehyoung Park; Taejung Park; Gun Sang Yoon; Eun-ho Choi; Jeongwoo Park
Optics Communications | 2014
Seo Hyun Kim; Hong Jin Kong; Soo Chang
Archive | 2013
Seo Hyun Kim; Gun Sang Yoon; Hyun-Hee Lee; Young Zo Yoo
Archive | 2013
June Hyoung Park; Young Zo Yoo; Tae Jung Park; Seo Hyun Kim; Il Hee Baek; Gun Sang Yoon; Eun Ho Choi
Archive | 2013
YoungZo Yoo; Seo Hyun Kim; June Hyoung Park; Il Hee Baek; Gun Sang Yoon; Hyun-Hee Lee; Eun Ho Choi