• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.10a
• /
• pp.533-535
• /
• 2018

As the use frequency of electronic communication equipment increases due to the influence of the 4th industrial revolution, the importance of image and signal processing is increasing. However, due to noise caused by various causes, the reliability of the equipment is degraded and malfunctions are caused. In this paper, we propose an algorithm to remove AWGN in most environments. The existing methods show relatively poor performance due to the smoothing phenomenon at the boundary of the image. To overcome this problem, we proposed a filter algorithm that adapts to the boundary region using the Sobel edge detection to remove the noise. And using the PSNR compared with traditional methods, such as to demonstrate the performance of the proposed algorithm.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.39 no.3
• /
• pp.225-231
• /
• 2011

The satellite clock anomalies, one of the abnormal signal factors of the GPS satellites, can have a significant impact on the GPS measurements. However, it can be difficult to detect the anomalies of the satellites clock before the range of the satellites clock error becomes bigger than the range of the other factors, due to the measurement including error of the orbit, ionosphere delay, troposphere delay, multipath and receiver clock. In order to perform quick and accurate detection by minimization of critical range in anomalies of the satellites clock, this paper suggested a solution to detect precise anomalies of the satellites clock after application of carrier smoothing filter from measurement by dual-frequency and adjustment of errors which can be occurred by other factor and the receiver clock errors. The performance of the proposed method was confirmed by comparing to the satellite clock biases which are provided by IGS.

• 한국ITS학회:학술대회논문집
• /
• 2010.05a
• /
• pp.184-187
• /
• 2010

RFID 기술은 각 사물에 전자태그를 부착하고, 사물의 고유 ID를 무선으로 인식하여, 해당 정보를 수집, 저장, 추적함으로써 사물에 대한 측위, 원거리 관리 및 사물 간 정보교환 등의 서비스를 제공하는 기술이다. RFID의 응용 분야의 하나로 전자태그가 부착되어 있는 대상의 위치를 실시간으로 파악하고 확인할 수 있는 RTLS(Real Time Locating Systems) 기술이 새로이 부각되고 있다. 본 논문에서는 AP의 RSSI(Received Signal Strength Indication)를 이용해 데이터의 정확도를 위해 약 30회의 위치 추정을 통한 위치 추정의 정확도를 알아보고 스무딩을 통한 측정 거리의 오차를 확인했다. AP의 RSSI를 통한 위치추정은 AP가 설치된 건물내의 실내환경에서 이루어졌으며, 비교적 정확한 약 3m의 오차를 보였고, 필터링을 통한 교통 추정값은 그보다 약 0.5~1m 향상된 성능을 보였다.

• Proceedings of the KIEE Conference
• /
• 2002.07d
• /
• pp.2105-2107
• /
• 2002

Geometry PIG 시스템은 배관의 상태 및 이상유무를 검사하여 그 결과를 저장하는 시스템으로 항법장치를 내장하고 있어 배관의 위치를 추정할 수 있다. PIG의 위치결정을 위해 후처리 보조 항법 알고리듬으로 비선형 스무딩 필터를 적용하고. 필터 측정치로 GPS를 이용한 위치기준점의 위치정보와 속도계를 이용한 속도정보를 사용하고, 특히 본 논문에서는 이들 정보 외에 Weld detector를 이용한 직선이동거리정보를 이용한 후처리 보조 항법 알고리듬을 PIG 시스템에 적용한다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.4
• /
• pp.973-979
• /
• 2011

In the transmitting process of image signal processing system, there are several different causes of degradation that have been occurring. The main cause of degradation is attributed to the noise. The most representive method of removing noise of image, which is caused by impulse noise environment, is using the SM(standard median filter). At edge, the filter has a special feature which has a tendency to decrease. As a result, we proposed a nonlinear filter that restores the image considering edge quality in the impulse noise environment. And through the simulation, we compared with the many of the conventional algorithms and the value of the PSNR(peak signal to nise ratio) is better than them and preserve the edge very well. So the nonlinear filter that proposed in this paper is excepted to help improve restoring the images that in impulse noise environment.

• Journal of Korea Game Society
• /
• v.3 no.1
• /
• pp.86-93
• /
• 2003

In this paper, we propose a new antialiasing method using filtering technique which is base on morphological pixel structure Aliasing occurs along the edge of lines and polygons. This undesirable effect happens because there are not enough pixels available on a typical monitor to properly display mathematically smooth lines and polygon edges. Aliasing can be very distracting. In a typical graphic scene, aliasing artifact will be visible along the edges of all objects that greatly diminish of realism. The proposed antialiasing method attempts to smooth extreme jagged contour lines and edges by properly handling pixel's structure, surface type and adjusting the pixel color according to the amount of pixel coverage. Next, we use filtering technique considering morphological pixel structure. Experimental results have shown that the propose algorithm achieves better performance in reducing noise for antialiasing. The method will be widely applied to basic antialiasing technique for computer graphic applications.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2020.07a
• /
• pp.429-432
• /
• 2020

본 논문에서는 카메라의 포커싱과 아웃포커싱에 의해 이미지에서 뿌옇게 표현되는 DoF(Depth of field, 피사계 심도) 영역을 합성곱 신경망을 통해 찾는 방법을 제안한다. 우리의 접근 방식은 RGB채널기반의 상호-상관 필터를 이용하여 DoF영역을 이미지로부터 효율적으로 분류하고, 합성곱 신경망 네트워크에 학습하기 위한 데이터를 구축하며, 이렇게 얻어진 데이터를 이용하여 이미지-DoF가중치 맵 데이터 쌍을 설정한다. 학습할 때 사용되는 데이터는 이미지와 상호-상관 필터 기반으로 추출된 DoF 가중치 맵을 이용하며, 네트워크 학습 단계에서 수렴률을 높이기 위해 스무딩을 과정을 한번 더 적용한 결과를 사용한다. 본 논문에서 제안하는 합성곱 신경망은 이미지로부터 포커싱과 아웃포커싱된 DoF영역을 자동으로 추출하는 과정을 학습시키기 위해 사용된다. 테스트 결과로 얻은 DoF 가중치 이미지는 입력 이미지에서 DoF영역을 빠른 시간 내에 찾아내며, 제안하는 방법은 DoF영역을 사용자의 ROI(Region of interest)로 활용하여 NPR렌더링, 객체 검출 등 다양한 곳에 활용이 가능하다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.26 no.2
• /
• pp.207-213
• /
• 2022

Recently, with the improvement of the performance of IoT technology and AI, automation and unmanned work are progressing in a wide range of fields, and interest in image processing, which is the basis of automation such as object recognition and object classification, is increasing. Image noise removal is an important process used as a preprocessing step in an image processing system, and various studies have been conducted. However, in most cases, it is difficult to preserve detailed information due to the smoothing effect in high-frequency components such as edges. In this paper, we propose an algorithm to restore damaged images in AWGN(additive white Gaussian noise) using fuzzy weights based on Gaussian distribution. The proposed algorithm switched the filtering process by comparing the filtering mask and the noise estimate with each other, and reconstructed the image by calculating the fuzzy weights according to the low-frequency and high-frequency components of the image.

• Journal of Institute of Control, Robotics and Systems
• /
• v.7 no.11
• /
• pp.944-952
• /
• 2001

Inertial navigation system(INS) errors increase with time due to inertial sensor errors, and therefore it is desired to combine INS with external aids such as GPS. However GPS informations have a randomly abrupt jump due to a sudden corruption of the received satellite signals and environment, and moreover GPS can\`t provide navigation solutions. In this paper, smoothing and prediction schemes are proposed for GPS`s jump or unavailable GPS. The smoothing algorithm which is designed as a scalar adaptive filter, smooths abrupt jump. The prediction algorithm which is proved by Schuler error model of INS, estimates INS error in appropriate time. The outputs of proposed algorithm apply stable measurements to GPS aided INS Kalman filter. Simulations show that the proposed algorithm can effectively remove measurement jump and predict INS error.

• MALSORI
• /
• no.67
• /
• pp.195-216
• /
• 2008

This paper addresses the problem of single-channel speech separation to extract the speech signal uttered by the speaker of interest from a mixture of speech signals. We propose to apply time-frequency smoothing to the existing statistical single-channel speech separation algorithms: The soft mask and the minimum-mean-square-error (MMSE) algorithms. In the proposed method, we use the two smoothing later. One is the uniform mask filter whose filter length is uniform at the time-Sequency domain, and the other is the met-scale filter whose filter length is met-scaled at the time domain. In our speech separation experiments, the uniform mask filter improves speaker-to-interference ratio (SIR) by 2.1dB and 1dB for the soft mask algorithm and the MMSE algorithm, respectively, whereas the mel-scale filter achieves 1.1dB and 0.8dB for the same algorithms.