• Title/Summary/Keyword: Laplacian image

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An Optimal Method to Improve the Visual Quality of Medical Images

  • Shin, Choong-ho;Jung, Chai-yeoung
    • Journal of Integrative Natural Science
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    • v.8 no.2
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    • pp.141-144
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    • 2015
  • As the visual quality of X-ray images is a critical reference for the accuracy of the clinical diagnosis, the methods to improve the quality of X-ray images have been investigated. Among many existing methods, using frequency domain filter is a very powerful method to improve the visual quality of images. In this paper, the inherent noises of the input images are suppressed by adding the Laplacian image to the subjected image. The medical X-ray images using the optimal high pass filter has shown improved edges. Further, the optimal high frequency emphasis filter has shown the improved contrast of flat areas by using the result image from the optimal high pass filter. Also the resulting images of the global contrast have improved by the histogram equalization. As a result, the proposed methods have shown enhanced contrast and edges of the images with noise canceling effect.

Development of a Tank Crew Protection System Using Moving Object Area Detection from Vision based (비전 기반 움직임 영역 탐지를 이용한 전차 승무원 보호 시스템 개발)

  • Choi, Kwang-Mo;Jang, Dong-Sik
    • Journal of the Korea Institute of Military Science and Technology
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    • v.8 no.2 s.21
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    • pp.14-21
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    • 2005
  • This paper describes the system for detecting the tank crew's(loader's) hand, arm, head and the upper half of the body in a danger area between the turret ceiling and the upper breech mechanism by computer vision-based method. This system informs danger of pressed to death to gunner and commander for the safety of operating mission. The camera mounted ort the top portion of the turret ceiling. The system sets search moving object from this image and detects by using change of image, laplacian operator and clustering algorithm in this area. It alarms the tank crews when it's judged that dangerous situation for operating mission. The result In this experiment shows that the detection rate maintains in $81{\sim}98$ percents.

Face Component Extraction Using Multiresolution Image (다해상도 영상을 이용한 얼굴 구성요소 추출)

  • Jang, Kyung-Shik
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.12
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    • pp.3675-3682
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    • 1999
  • This paper proposes the method to extract face components without using the color information and the motion information in a gray image. A laplacian pyramid of the original image is built. Eye and nose candidates are extracted using only the gray information in a low resolution laplacian image and pairs are found that consist of two eye candidates and a nose one. At full resolution, horizontal and vortical edges are found in the regions of face components which are established using the candidates. Using those edge informations, face components are extracted. The experiments have been performed for images with various sizes and positions of face, and show very encouraging result.

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An Edge Detection Method for Gray Scale Images Based on their Fuzzy System Representation

  • Moon, Byung-Soo;Lee, Hyun-Chul;Kim, Jang-Yeol
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2001.12a
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    • pp.283-286
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    • 2001
  • Based on a fuzzy system representation of gray scale images, we derive an edge detection algorithm whose convolution kernel is different from the known kernels such as those of Roberts', Prewitt's or Sobel's gradient. Our fuzzy system representation is an exact representation of the bicubic spline function which represents the gray scale image approximately. Hence the fuzzy system is a continuous function and it provides a natural way to define the gradient and the Laplacian operator. We show that the gradient at grid points can be evaluated by taking the convolution of the image with a 3 3 kernel. We also show that our gradient coupled with the approximate value of the continuous function generates an edge detection method which creates edge images clearer than those by other methods. A few examples of applying our methods are included.

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Development of Real-time Landslide Inspecting and Monitoring System

  • Hur Chul;Jeon, Yang-Bae;Kim, Choon-Sik;Kim, Sang-Bong
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.243-243
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    • 2000
  • This paper introduces a visual inspecting and monitoring system based on an image processing technique. We propose an image processing method for analyzing landslide movement in real time. The method adopts Laplacian of Gaussian operator to extract linear features for the captured images and uses a linear matching algorithm to distinguish the matching error for those features. When the algorithm is processed, motion parameters such as displacement area and its direction are computed. Once movement is recognized, displacements are estimated graphically with statistical amount in the image plane. The simulation results are shown us to verify the effectiveness of the developed method.

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Identification Method of Geometric and Filtering Change Regions in Modified Digital Images (수정된 디지털 이미지에서 기하학적 변형 및 필터링 변형 영역을 식별하는 기법)

  • Hwang, Min-Gu;Cho, Byung-Joo;Har, Dong-Hwan
    • Journal of Korea Multimedia Society
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    • v.15 no.11
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    • pp.1292-1304
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    • 2012
  • Recently, digital images are extremely forged by editors or advertisers. Also, amateurs can modify images throughout easy editing programs. In this study, we propose identification and analytical methods for the modified images to figure out those problems. In modified image analysis, we classify two parts; a filtering change and a geometric change. Those changes have an algorithm based on interpolation so that we propose the algorithm which is able to analyze a trace on a modified area. With this algorithm, we implement a detection map of interpolation using minimum filter, laplacian algorithm, and maximum filter. We apply the proposed algorithm to modified image and are able to analyze its modified trace using the detection map.

An edge detection method for gray scale images based on their fuzzy system representation (디지털 영상의 퍼지시스템 표현을 이용한 Edge 검출방법)

  • 문병수;이현철;김장열
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.6
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    • pp.454-458
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    • 2001
  • Based on a fuzzy system representation of gray scale images, we derive and edge detection algorithm whose convolution kernel is different from the known kernels such as those of Robert's Prewitt's or Sobel's gradient. Our fuzzy system representation is an exact representation of the bicubic spline function which represents the gray scale image approximately. Hence the fuzzy system is a continuous function and it provides a natural way to define the gradient and the Laplacian operator. We show that the gradient at grid points can be evaluated by taking the convolution of the image with a 3$\times$3 kernel. We also that our gradient coupled with the approximate value of the continuous function generates an edge detection method which creates edge images clearer than those by other methods. A few examples of applying our methods are included.

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The Image Restoration using Dual Adaptive Regularization Operators (이중적 정칙화 연산자를 사용한 영상복원)

  • 김승묵;전우상;이태홍
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.1B
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    • pp.141-147
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    • 2000
  • In the restoration of degraded noisy motion blurred image, we have trade-off problem between smoothing the noise and restoration of the edge region. While the noise is smoothed, die edge or details will be corrupted. On the other hand, restoring the edge will amplify the noise. To solve this problem we propose an adaptive algorithm which uses I- H regularization operator for flat region and Laplacian regularization operator for edge region. Through the experiments, we verify that the proposed method shows better results in the suppression of the noise amplification in flat region, introducing less ringing artifacts in edge region and better ISNR than those of the conventional ones.

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An Algorithm on Edge Detection using Local Mask in Salt & Pepper Noise Environments (Salt & Pepper 잡음 환경에서 국부 마스크를 이용한 에지 검출에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.787-789
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    • 2014
  • Image processing is presently used in various areas such as smart phone, smart TV, and portable PC. Likewise, edge detection plays an important role in most of the applications. As such, studies for the detection of edge are continually underway. Roberts, Laplacian and LoG(lapacian of Gaussian) are the representative edge detection methods, but these methods do not offer optimal edge detection characteristic in case of the image that is damaged by Salt & Pepper noises. As such, this study presented algorithm with superior edge detection characteristic by utilizing the elements of local mask in Salt & Pepper noise environment.

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An Enhancement Technique for Backlit Images using Laplace Pyramid Fusion (라플라스 피라미드 융합을 이용한 역광영상의 개선 방법)

  • Kim, Jin Heon
    • Journal of IKEEE
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    • v.26 no.2
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    • pp.292-298
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    • 2022
  • There is a limit to improving the image quality through global processing of images taken under backlighting because too bright and dark parts are mixed in one scene. This paper introduces a method to improve the quality of a photo by making two virtual images that improve the dark and bright areas of a backlit photo, and fusing them with the original image into a Laplacian pyramid. The proposed method reduces the computational burden by using histogram stretching and gamma transformation that can be simplified with LUT when creating the two virtual images. In addition, in order to obtain a color-enhanced image, contrast conversion was performed only on the luminance using the HSV coordinate system. The proposed technique showed its effectiveness by calculating several NIQA indicators using standard image data sets.