• Title/Summary/Keyword: real-time embedded Linux

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Design and Implementation of Kernel-Level Split and Merge Operations for Efficient File Transfer in Cyber-Physical System (사이버 물리 시스템에서 효율적인 파일 전송을 위한 커널 레벨 분할 및 결합 연산의 설계와 구현)

  • Park, Hyunchan;Jang, Jun-Hee;Lee, Junseok
    • IEMEK Journal of Embedded Systems and Applications
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    • v.14 no.5
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    • pp.249-258
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    • 2019
  • In the cyber-physical system, big data collected from numerous sensors and IoT devices is transferred to the Cloud for processing and analysis. When transferring data to the Cloud, merging data into one single file is more efficient than using the data in the form of split files. However, current merging and splitting operations are performed at the user-level and require many I / O requests to memory and storage devices, which is very inefficient and time-consuming. To solve this problem, this paper proposes kernel-level partitioning and combining operations. At the kernel level, splitting and merging files can be done with very little overhead by modifying the file system metadata. We have designed the proposed algorithm in detail and implemented it in the Linux Ext4 file system. In our experiments with the real Cloud storage system, our technique has achieved a transfer time of up to only 17% compared to the case of transferring split files. It also confirmed that the time required can be reduced by up to 0.5% compared to the existing user-level method.

Fixed-Wing UAV's Image-Based Target Detection and Tracking using Embedded Processor (임베디드 프로세서를 이용한 고정익 무인항공기 영상기반 목표물 탐지 및 추적)

  • Kim, Jeong-Ho;Jeong, Jae-Won;Han, Dong-In;Heo, Jin-Woo;Cho, Kyeom-Rae;Lee, Dae-Woo
    • Journal of Advanced Navigation Technology
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    • v.16 no.6
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    • pp.910-919
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    • 2012
  • In this paper, we described development of on-board image processing system and its process and verified its performance through flight experiment. The image processing board has single ARM(Advanced Risk Machine) processor. We performed Embedded Linux Porting. Algorithm to be applied for object tracking is color-based image processing algorithm, it can be designed to track the object that has specific color on ground in real-time. To verify performance of the on-board image processing system, we performed flight test using the PNUAV, UAV developed by LAB. Also, we performed optimization of the image processing algorithm and kernel to improve real-time performance. Finally we confirmed that proposed system can track the blue-color object within four pixels error range consistently in the experiment.

Character Segmentation in a Grayscale Image using the Standard Deviation (그레이스케일 영상에서 표준 편차를 이용한 문자 분할)

  • Jung, Min Chul
    • Journal of the Semiconductor & Display Technology
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    • v.11 no.2
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    • pp.27-31
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    • 2012
  • This paper proposes a new method of character segmentation in a grayscale image using the standard deviation. Firstly, the proposed method scans vertically the region of interest in an image in order to calculate a standard deviation for each scan line. Characters' standard deviations are much bigger than the background's. Therefore, it is possible to segment characters vertically using the differentiation of those two types of standard deviations. Secondly, the method scans each vertically segmented image horizontally at this time, and then segments each image similarly. The proposed method is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiments were conducted by using credit card images. The results show that the proposed algorithm is quite successful for most credit cards. However, the method fails in some credit cards with strong background patterns.

Design and Implementation of an Embedded Audio Video Bridging Platform for Multichannel Multimedia Transmission (다채널 멀티미디어 전송용 임베디드 Audio Video Bridging 플랫폼 설계 및 구현)

  • Wee, Jungwook;Park, Kyoungwon;Kwon, Kiwon;Song, Byoungchul;Kang, Mingoo
    • Journal of Internet Computing and Services
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    • v.16 no.2
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    • pp.1-6
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    • 2015
  • In this paper, we designed an embedded audio video bridging (AVB) platform based on IEEE 802.1BA for real-time multimedia transmission in smart-car, smart-home, smart-theater, and then evaluated a performance of the implemented platform by analysis of IEEE 802.1AS (time synchronization protocol) and IEEE 802.1Qat (stream reservation protocol). Especially, the AVB Layer-2 protocol of MRP(Multiple Registration Protocol), MMAP(Multicast Address Acquisition Protocol), IEEE 1722, 1722.1 etc. was and implemented by linux based operating system. It is shown by interoperability tests with commercial products that the implemented platform transmits real-time multichannel AV data over AVB networks for Multichannel Multimedia Transmission.

Detection and Recognition of Vehicle Brake Lights using an R-Filtering (R-필터링을 이용한 자동차 브레이크등 검출과 인식)

  • Jung, Min-Chul
    • Journal of the Semiconductor & Display Technology
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    • v.10 no.4
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    • pp.95-100
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    • 2011
  • This paper proposes a new method of vehicle brake lights detection and recognition using an R-filtering. Firstly, the proposed method processes the R-filtering with the first input image and then with the second one in order to detect brake lights. Secondly, the method counts the number of red pixels and computes the mean value in each R-filtered image. The difference rates between the numbers of the red pixels and between the mean values of two images are defined in this paper. Through the analysis of the difference rates, it can recognize whether brake lights are turned on or off, and whether the vehicle ahead is being approached or not. The proposed method is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiment results show that the proposed algorithm is quite successful.

PCB Defects Detection using Connected Component Classification (연결 성분 분류를 이용한 PCB 결함 검출)

  • Jung, Min-Chul
    • Journal of the Semiconductor & Display Technology
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    • v.10 no.1
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    • pp.113-118
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    • 2011
  • This paper proposes computer visual inspection algorithms for PCB defects which are found in a manufacturing process. The proposed method can detect open circuit and short circuit on bare PCB without using any reference images. It performs adaptive threshold processing for the ROI (Region of Interest) of a target image, median filtering to remove noises, and then analyzes connected components of the binary image. In this paper, the connected components of circuit pattern are defined as 6 types. The proposed method classifies the connected components of the target image into 6 types, and determines an unclassified component as a defect of the circuit. The analysis of the original target image detects open circuits, while the analysis of the complement image finds short circuits. The machine vision inspection system is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiment results show that the proposed algorithms are quite successful.

Traffic Signal Detection and Recognition in an RGB Color Space (RGB 색상 공간에서 교통 신호등 검출과 인식)

  • Jung, Min-Chul
    • Journal of the Semiconductor & Display Technology
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    • v.10 no.3
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    • pp.53-59
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    • 2011
  • This paper proposes a new method of traffic signal detection and recognition in an RGB color model. The proposed method firstly processes RGB-filtering in order to detect traffic signal candidates. Secondly, it performs adaptive threshold processing and then analyzes connected components of the binary image. The connected component of a traffic signal has to be satisfied with both a bounding box rate and an area rate that are defined in this paper. The traffic signal recognition system is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiment results show that the proposed algorithms are quite successful.

Image Enhancement of an Infrared Thermal Camera Using Edge Detection Methods (에지 검출 방법을 이용한 열화상 카메라의 영상 개선)

  • Jung, Min Chul
    • Journal of the Semiconductor & Display Technology
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    • v.15 no.3
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    • pp.51-56
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    • 2016
  • This paper proposes a new image enhancement method for an infrared thermal image. The proposed method uses both Laplacian and Prewitt edge detectors. Without a visible light, it uses an infrared image for the edge detection. The method subtracts contour images from the infrared thermal image. It results black contours of objects in the infrared thermal image. That makes the objects in the infrared thermal image distinguished clearly. The proposed method is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiments were conducted by using various infrared thermal images. The results show that the proposed method is successful for image enhancement of an infrared thermal image.

Infrared Image Enhancement Using A Histogram Partition Stretching and Shrinking Method (히스토그램 분할 펼침과 축소 방법을 이용한 적외선 영상 개선)

  • Jung, Min Chul
    • Journal of the Semiconductor & Display Technology
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    • v.14 no.4
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    • pp.50-55
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    • 2015
  • This paper proposes a new histogram partition stretching and shrinking method for infrared image enhancement. The proposed method divides the histogram of an input image into three partitions according to its mean value and standard deviation. The method stretches both the dark partition and the bright partition of the histogram, while it shrinks the medium partition. As the result, both the dark part and the bright part of the image have more brightness levels. The proposed method is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiments were conducted by using various infrared images. The results show that the proposed algorithm is successful for the infrared image enhancement.

Study on Machine Vision Algorithms for LCD Defects Detection (LCD 결함 검출을 위한 머신 비전 알고리즘 연구)

  • Jung, Min-Chul
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.3
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    • pp.59-63
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    • 2010
  • This paper proposes computer visual inspection algorithms for various LCD defects which are found in a manufacturing process. Modular vision processing steps are required in order to detect different types of LCD defects. Those key modules include RGB filtering for pixel defects, gray-scale morphological processing and Hough transform for line defects, and adaptive threshold for spot defects. The proposed algorithms can give users detailed information on the type of defects in the LCD panel, the size of defect, and its location. The machine vision inspection system is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiment results show that the proposed algorithms are quite successful.