• Title/Summary/Keyword: Image Edge

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A Spatial Error Concealment Using Pixelwise Fine Directional Interpolation (픽셀 단위의 정밀한 방향성 보간을 이용한 공간적 에러 은닉 기법)

  • Kim, Won-Ki;Koo, Ja-Sung;Jin, Soon-Jong;Jeong, Je-Chang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.2C
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    • pp.124-131
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    • 2007
  • This paper presents a block loss recovery technique for the image block data corrupted by transmission losses through the employment of fine directional interpolation (FDI). The proposed algorithm introduces a spatial direction vector (SDV). The SDVs are extracted from the edge information of the neighboring image data. Subsequently, the SDVs are adaptively applied to interpolate lost pixels on a pixel-by-pixel basis. This approach improves the capability to more reliably recover high-detailed contents in the corrupted block. Experimental results demonstrate that the FDI method performs better as compared to previous techniques.

Removal of the Ambiguity of Images by Normalization and Entropy Minimization and Edge Detection by Understanding of Image Structures (정규화와 엔트로피의 최소화에 의한 영상 경계의 애매성 제거 및 영상 구조 파악에 의한 경계선 추출)

  • Jo, Dong-Uk;Baek, Seung-Jae
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.9
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    • pp.2558-2562
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    • 1999
  • This paper proposes on the methods of noise removal and edge extraction which is done by eliminating the ambiguities of the image using normalization and minimizing the entropy. Pre-existing methods have their own peculiarities and limitations, such as gray level distributions change very slowly or two regions which having similar gray level distribution are touched. This affects on the post processing such as feature extraction, as a result, this leads to false-recognition or no-recognition. Therefore, this paper proposes on the methods which overcome these problems. Finally, the effectiveness of this paper is demonstrated by several experiments.

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Salt and Pepper noise Removal for Edge Preservation (에지 보존을 위한 Salt and Pepper 잡음 제거)

  • Kwon, Se-Ik;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.10a
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    • pp.694-696
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    • 2017
  • Image processing is being hailed as an important field with various applications as the digital information era advances. In particular, studies on methods to remove noise from images are being actively undertaken. This paper suggests an image restoration filter that processes through a weighted filter in accordance with the direction of partial masks to preserve edge while replacing the noise in the images with neighboring pixels. The PSNR(peak signal to noise ratio) was used as a tool to objectively judge the improvement effects compared to existing methods.

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A Study on 3D Road Extraction From Three Linear Scanner

  • Yun, SHI;SHIBASAKI, Ryosuke
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.301-303
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    • 2003
  • The extraction of 3D road network from high-resolution aerial images is still one of the current challenges in digital photogrammetry and computer vision. For many years, there are many researcher groups working for this task, but unt il now, there are no papers for doing this with TLS (Three linear scanner), which has been developed for the past several years, and has very high-resolution (about 3 cm in ground resolution). In this paper, we present a methodology of road extraction from high-resolution digital imagery taken over urban areas using this modern photogrammetry’s scanner (TLS). The key features of the approach are: (1) Because of high resolution of TLS image, our extraction method is especially designed for constructing 3D road map for next -generation digital navigation map; (2) for extracting road, we use the global context of the intensity variations associated with different features of road (i.e. zebra line and center line), prior to any local edge. So extraction can become comparatively easy, because we can use different special edge detector according different features. The results achieved with our approach show that it is possible and economic to extract 3D road data from Three Linear Scanner to construct next -generation digital navigation road map.

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Land cover classification of a non-accessible area using multi-sensor images and GIS data (다중센서와 GIS 자료를 이용한 접근불능지역의 토지피복 분류)

  • Kim, Yong-Min;Park, Wan-Yong;Eo, Yang-Dam;Kim, Yong-Il
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.5
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    • pp.493-504
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    • 2010
  • This study proposes a classification method based on an automated training extraction procedure that may be used with very high resolution (VHR) images of non-accessible areas. The proposed method overcomes the problem of scale difference between VHR images and geographic information system (GIS) data through filtering and use of a Landsat image. In order to automate maximum likelihood classification (MLC), GIS data were used as an input to the MLC of a Landsat image, and a binary edge and a normalized difference vegetation index (NDVI) were used to increase the purity of the training samples. We identified the thresholds of an NDVI and binary edge appropriate to obtain pure samples of each class. The proposed method was then applied to QuickBird and SPOT-5 images. In order to validate the method, visual interpretation and quantitative assessment of the results were compared with products of a manual method. The results showed that the proposed method could classify VHR images and efficiently update GIS data.

Digital Watermarking Algorithm of Still Image Using Human Visual System Characteristics (인간시각체계 특성을 이용한 정지영상 디지털 워터마킹 알고리즘)

  • 지남현;전병민
    • The Journal of the Korea Contents Association
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    • v.3 no.2
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    • pp.31-38
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    • 2003
  • This paper proposes method to insert soong Watermark considering dull HVS properties to big change of Edge and Texture area. While conversion of existent Fourier form can acquire information for whole frequency ingredient of image, but Wavelet transform can look for Edge and Texture area locally. Therefore, use Wavelet transform to use HVS properites, and compare with Xia's Watermarking techniques to use Wavelet transform simply arid experimented these proposal algorithm. Experimented about fidelity and robusthness by attack method that is used in existing paper, and as a result, confirmed that proposal algorithm that use HVS properties is more superior than Xia's techniques.

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A Study on Improvement of Image Processing for Precision Inner Diameter Measurement of Circular Hole (원형구멍 정밀 내경측정을 위한 영상처리 개선에 관한 연구)

  • Park, ChangYong;Kweon, HyunKyu;Li, JingHua;Zhang, Hua Xin
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.3
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    • pp.8-13
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    • 2017
  • In this paper, the measurement of the inner diameter dimension of the circular hole by using a machine vision system was studied. This paper was focused on the theory and key technologies of machine vision inspection technology for the improvement of measurement accuracy and speed of the micro circular holes. A new method was proposed and was verified through the experiments on Gray conversion, binarization, edge extraction and Hough transform in machine vision system processes. Firstly, the Hough transform was proposed in order to improve the speed increase and implementation ease, it demonstrated the superiority of Hough transform and improvement through a comparative experiment. Secondly, we propose a calibration method of the system in order to obtain exactly the inner diameter of the circular hole. Finally, we demonstrate the reliability of the entire system as a MATLAB-based implementation of the GUI program, measuring the inner diameter of the circular hole through the circular holes of different dimensions measuring experiment.

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Visual Inspection of Tube Internal

  • Choi, Young-Soo;Cho, Jai-Wan;Kim, Chang-Hoi;Seo, Yong-Chil;Kim, Seung-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.789-792
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    • 2003
  • Pipe inspection has a great importance to ensure safety for the nuclear power plant. In this paper, we designed visual inspection module for the tube internal, which diameter is 15${\sim}$20mm. And we made inspection module which consisted of CCD camera and light. And the relation between image and real world coordinate is established. Image processing is performed to calculate mapping parameter and analyze the size of defect. For the calculation of mapping parameter, experiment is performed using grid type test pattern. Acquired image is processed to extract image coordinate. Edge detection, thresholding, median filtering and morphology filtering is applied to extract grid pattern. Extracted image coordinate is used to calculate image to real world mapping. Lens distortion was considered and corrected to get exact data. Coordinate transformation data is provided for the users to recognize easily. Experiment was performed using grid type test pattern, we extracted lens distortion parameter and real coordinate of defect point. Radial distortion of lens was corrected but tangential distortion was not considered. As continuum to this study, the tangential distortion of lens is considered and improvement of analy zing technique for the tube internal be explored continuously.

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Restoration of Landsat ETM+ SLC-off Gaps Using SPOT Image (SPOT 영상을 이용한 Landsat-7의 SLC-off 영상 복원)

  • Kim Hye-Jin;Yu Ki-Yun;Kim Yong-Il
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.229-234
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    • 2006
  • On May 31, 2003. Landsat 7 experienced an anomaly causing the Scan Line Corrector(SLC) to stop functioning normally. The SLC-off causes individual scan lines to alternately overlap and then leave large gaps at the edge of the Image. A many scientists with ongoing experience using ETM+ data evaluated the scientific usability and validity of Landsat 7 products containing the SLC anomaly The best reference scene for gap-filling is the other SLC-on Landsat scene that provide same resolution, few changes, and similar data acquisition. But receiving of Landsat imagery is not stable in Korea. So SPOT image can be another alternative solution because it is a steady-state multispectral satellite image as Landsat image. In this study, we filled the SLC-off gap s of 2, 3, 4 bands using SPOT image by a local regression technique, and assigned the optimum spectral value to gaps of 1, 5, 7 bands based on a spectral adjacency. Through this process, we could restore Landsat SLC-off image and evaluated the accuracy of the results.

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Rock Fracture Centerline Extraction based on Hessian Matrix and Steger algorithm

  • Wang, Weixing;Liang, Yanjie
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.12
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    • pp.5073-5086
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    • 2015
  • The rock fracture detection by image analysis is significant for fracture measurement and assessment engineering. The paper proposes a novel image segmentation algorithm for the centerline tracing of a rock fracture based on Hessian Matrix at Multi-scales and Steger algorithm. A traditional fracture detection method, which does edge detection first, then makes image binarization, and finally performs noise removal and fracture gap linking, is difficult for images of rough rock surfaces. To overcome the problem, the new algorithm extracts the centerlines directly from a gray level image. It includes three steps: (1) Hessian Matrix and Frangi filter are adopted to enhance the curvilinear structures, then after image binarization, the spurious-fractures and noise are removed by synthesizing the area, circularity and rectangularity; (2) On the binary image, Steger algorithm is used to detect fracture centerline points, then the centerline points or segments are linked according to the gap distance and the angle differences; and (3) Based on the above centerline detection roughly, the centerline points are searched in the original image in a local window along the direction perpendicular to the normal of the centerline, then these points are linked. A number of rock fracture images have been tested, and the testing results show that compared to other traditional algorithms, the proposed algorithm can extract rock fracture centerlines accurately.