• 한국통신학회논문지
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• 제32권8C호
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• pp.696-702
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• 2007

This paper proposes a regional feature preserving adaptive interpolation algorithm for natural images. The algorithm can be used in resolution enhancement, arbitrary rotation and other applications of still images. The basic idea is to first scan the sample image to initialize a 2D array which records the edge direction of all four-pixel squares, and then use the array to adapt the interpolation at a higher resolution based on the edge structures. A hybrid approach of switching between bilinear and triangulation-based interpolation is proposed to reduce the overall computational complexity. The experiments demonstrate our adaptive interpolation and show higher PSNR results of about max 2 dB than other traditional interpolation algorithms.

• Journal of Communications and Networks
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• 제12권1호
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• pp.5-10
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• 2010

This paper introduces a new fast motion estimation based on estimating a block matching error (i.e., sum of absolute difference (SAD)) between blocks which can eliminate an impossible candidate block much earlier than a conventional partial distortion elimination (PDE) scheme. The basic idea of the proposed scheme is based on predicting the total SAD of a candidate block using its partial SAD. In particular, in order to improve prediction accuracy and computational efficiency, a sub-sample based block matching and a selective pixel-based approaches are employed. In order to evaluate the proposed scheme, several baseline approaches are described and compared. The experimental results show that the proposed algorithm can reduce the computations by about 44% for motion estimation at the cost of 0.0005 dB quality degradation versus the general PDE algorithm.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권3호
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• pp.166-173
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• 2005

Preserving image features, edges and details in the process of impulsive noise filtering is an important problem. To avoid image blurring, only corrupted pixels must be filtered. In this paper, we propose an effective impulse noise detection method using Self-Organizing Neural Network(SONN) which applies median filter selectively for removing random-valued impulse noises while preserving image features, edges and details. Using a $3\times3$ window, we obtain useful local features with which impulse noise patterns are classified. SONN is trained with sample image patterns and each pixel pattern is classified by its local information in the image. The results of the experiments with various images which are the noise range of $5-15\%$ show that our method performs better than other methods which use multiple threshold values for impulse noise detection.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2015년도 하계학술대회
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• pp.433-434
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• 2015

카메라 캘리브레이션은 다시점 카메라 시스템에서 내부와 외부 인자로 이루어진 카메라 파라미터를 획득하는 과정을 의미 한다. 이는 3차원으로 표현되는 장면과 카메라간의 구조를 다루기 위해 중요하다. 그러나 카메라 캘리브레이션은 사람이 직접 손으로 각 영상에서 사각형의 네 점을 정확히 찍어 주어야 하는 과정 때문에 카메라의 수와 패턴 영상의 수가 늘어남에 따라 상당히 번거로운 작업이 된다. 본 논문에서는 카메라 캘리브레이션 과정에서 손으로 수행하는 작업을 줄이기 위해 자동으로 패턴 특징점을 탐색하는 알고리즘을 제안한다. 제안하는 방법은 먼저 영상에서 패턴 특징점의 후보를 찾기 위해 해리스 코너 검출 방법을 사용한다. 그리고 후보 주변의 원형 샘플 화소를 이용하여 유효한 패턴 특징점을 추출한다. 실험 결과는 Matlab 캘리브레이션 툴박스를 이용하여 획득한 카메라 파라미터와 비교해 보았을 때 큰 차이가 없지만 수작업의 번거로움을 상당히 감소시켰음을 확인하였다.

• Journal of Information Processing Systems
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• 제14권4호
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• pp.877-891
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• 2018

In this paper, we propose a novel algorithm for rendering motion-blurred shadows utilizing a depth-time ranges shadow map. First, we render a scene from a light source to generate a shadow map. For each pixel in the shadow map, we store a list of depth-time ranges. Each range has two points defining a period where a particular geometry was visible to the light source and two distances from the light. Next, we render the scene from the camera to perform shadow tests. With the depths and times of each range, we can easily sample the shadow map at a particular receiver and time. Our algorithm runs entirely on GPUs and solves various problems encountered by previous approaches.

• Journal of Electrical Engineering and Technology
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• 제7권2호
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• pp.221-224
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• 2012

We propose a Readout Integrated Circuit (ROIC), which applies a fixed current bias sensing method to the input stage in order to simplify the circuit structure and the infrared sensor characteristic control. For the sample-and-hold stage to display and control a signal detected by the infrared sensor using a two-dimensional (2D) focal plane array, a differential delta sampling (DDS) circuit is proposed, which effectively removes the FPN. In addition, the output characteristic is improved to have wider bandwidth and higher gain by applying a two-stage variable gain amplifier (VGA). The output characteristic of the proposed device was 23.91 mV/$^{\circ}C$, and the linearity error rate was less than 0.22%. After checking the performance of the ROIC using HSPICE simulation, the chip was manufactured and measured using the SMIC 0.35 um standard CMOS process to confirm that the simulation results from the actual design are in good agreement with the measurement results.

• Journal of Information Processing Systems
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• 제17권4호
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• pp.737-753
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• 2021

As the demand for high-quality rendering for mixed reality, videogame, and simulation has increased, global illumination has been actively researched. Monte Carlo path tracing can realize global illumination and produce photorealistic scenes that include critical effects such as color bleeding, caustics, multiple light, and shadows. If the sampling rate is insufficient, however, the rendered results have a large amount of noise. The most successful approach to eliminating or reducing Monte Carlo noise uses a feature-based filter. It exploits the scene characteristics such as a position within a world coordinate and a shading normal. In general, the techniques are based on the denoised pixel or sample and are computationally expensive. However, the main challenge for all of them is to find the appropriate weights for every feature while preserving the details of the scene. In this paper, we compare the recent algorithms for removing Monte Carlo noise in terms of their performance and quality. We also describe their advantages and disadvantages. As far as we know, this study is the first in the world to compare the artificial intelligence-based denoising methods for Monte Carlo rendering.

• 천문학회보
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• 제45권1호
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• pp.61.3-61.3
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• 2020

We present spatially resolved outflows and photoionization for a pilot sample of 11 type 1 AGNs (z<0.3) based on the Gemini Multi-Object Spectrograph Integral Field Unit data. These AGNs were selected since we found strong outflow signatures in SDSS spectra. We focus on [OIII] and Hα emission lines to probe outflow kinematics by measuring line flux, velocity, and velocity dispersion at each pixel. We investigate characteristics of gas kinematics of type 1 AGNs and compare them with those of type 2 AGNs in our previous studies. Furthermore, by drawing BPT map, photoionization states will be also discussed. Based on the results, we discuss various implications on the impacts of outflows on star formation in host galaxies.

• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.252-259
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• 2017

Nowadays, the existing manual method for recording actual progress of the construction site has some drawbacks, such as great reliance on the experience of professional engineers, work-intensive, time consuming and error prone. A method integrating computer vision and BIM(Building Information Modeling) is presented for indoor automatic progress monitoring. The developed method can accurately calculate the engineering quantity of target component in the time-lapse images. Firstly, sample images of on-site target are collected for training the classifier. After the construction images are identified by edge detection and classifier, a voting algorithm based on mathematical geometry and vector operation will divide the target contour. Then, according to the camera calibration principle, the image pixel coordinates are conversed into the real world Coordinate and the real coordinates would be corrected with the help of the geometric information in BIM model. Finally, the actual engineering quantity is calculated.

• 한국통신학회논문지
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• 제30권4C호
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• pp.276-282
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• 2005

산업, 의용, 교통, 사회의 각 분야에서 응용되고 있는 산업용 텔레비전(Industrial Television : ITV)을 사용하여 동영상의 실시간 자동처리 방법에 의한 고속도로 및 일반도로상의 교통류 및 차량의 속도를 계측하는 시스템과 알고리즘을 개발하였다. 영상 계측 시스템에서는 ITV에 의한 실시간 처리를 가능하게 하기 위하여, 화면의 전화소를 처리하는 대신에 화면상에 미리 설정한 비교적 소수의 샘플점의 휘도 정보만을 취급하는 프레임 그레버를 사용하고, 그 시스템으로 각종 동영상의 처리 알고리즘을 개발하였다. 통과 차량의 대수의 계측은 시간적인 정보를 활용하는 것으로, 차량의 대략적인 윤곽을 그린 다음 그 윤곽의 선두 부분을 인식하는 기법에 의해서 1레인뿐만 아니라 많은 레인에 걸친 통과 차량을 계측할 수 있는 특징을 가지고 있다. 실제로, ITV 영상을 이용하여 고속도로 및 일반도로상에서 도로의 횡단 방향에 하나의 샘플열을 설치하고, 계측 알고리즘을 개발하였다. 또한 이 기법을 이용하여, 통과차량에 대하여 일정거리를 둔 2개의 샘플점 열을 설치하구 윤곽처리를 한 다음, 그 윤곽의 프레임수와 거리를 이용하여 차량의 속도를 계측하는 알고리즘을 개발하였다.