• Title/Summary/Keyword: Image Edge

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A Study on Image Pixel Classification Using Directional Scales (방향성 정보 척도를 이용한 영상의 픽셀분류 방법에 관한 연구)

  • 박중순;김수겸
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.4
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    • pp.587-592
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    • 2004
  • Pixel classification is one of basic issues of image processing. The general characteristics of the pixels belonging to various classes are discussed and the radical principles of pixel classification are given. At the same time, a pixel classification scheme based on image information scales is proposed. The proposed method is overcome that computation amount become greater and contents easily get turned. And image directional scales has excellent anti-noise performance. In the result of experiment. good efficiency is showed compare with other methods.

Profile Measurement System of Train Wheel with Image Processing (이미지 처리기술을 이용한 차륜형상 측정장치 개발)

  • 김기택;김만배;김봉택
    • Proceedings of the KSR Conference
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    • 1998.11a
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    • pp.595-600
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    • 1998
  • Train wheels tend to wear abrasion due to frequent Starlings and brakings. They are important factors of train safety and noise. However, it is difficult and inaccurate to measure their shape and profile manually. Profile measurement system of train wheel with image processing is proposed. The system consists of CCD cameras, PCI image grabber board, and PC operated on Windows '95. Image processing algorithms such as filtering, histogram equalization, and edge detection are presented, and some processing results are illustrated.

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Stereo Matching for PCB Image (PCB 영상의 스테레오 정합)

  • 최춘호;문철홍
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.943-946
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    • 1998
  • In this paper, we applied FFT to PCB Images, cutting unnecessary singals and noise, moving the starting point to center of image and used rotaion transform. from the detected edge Hough Transform identify the length, but not the angle, so we matched PCB images with using rotation transform to identify length and angle. After rotation transform we employ Least Squared Method to exact stereo matching.

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A Seamline Extraction Technique Considering the Characteristic of NDVI for High Resolution Satellite Image Mosaics (고해상도 위성영상 모자이크를 위한 NDVI 특성을 이용한 접합선 추출 기법)

  • Kim, Jiyoung;Chae, Taebyeong;Byun, Younggi
    • Korean Journal of Remote Sensing
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    • v.31 no.5
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    • pp.395-408
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    • 2015
  • High-resolution satellite image mosaics are becoming increasingly important in the field of remote sensing image analysis as an essential image processing to create a large image constructed from several smaller images. In this paper, we present an automatic seamline extraction technique and the procedure to generate a mosaic image by this technique. For more effective seamline extraction in the overlap region of adjacent images, an NDVI-based seamline extraction technique is developed, which takes advantage of the computational time and memory. The Normalized Difference Vegetation Index(NDVI) is an index of plant "greeness" or photosynthetic activity that is employed to extract the initial seamline. The NDVI can divide into manmade region and natural region. The cost image is obtained by the canny edge detector and the buffering technique is used to extract the ranging cost image. The seamline is extracted by applying the Dijkstra algorithm to a cost image generated through the labeling process of the extracted edge information. Histogram matching is also conducted to alleviate radiometric distortion between adjacent images acquired at different time. In the experimental results using the KOMPSAT-2/3 satellite imagery, it is confirmed that the proposed method greatly reduces the visual discontinuity caused by geometric difference of adjacent images and the computation time.

A Study on the Improvement of the Facial Image Recognition by Extraction of Tilted Angle (기울기 검출에 의한 얼굴영상의 인식의 개선에 관한 연구)

  • 이지범;이호준;고형화
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.7
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    • pp.935-943
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    • 1993
  • In this paper, robust recognition system for tilted facial image was developed. At first, standard facial image and lilted facial image are captured by CCTV camera and then transformed into binary image. The binary image is processed in order to obtain contour image by Laplacian edge operator. We trace and delete outermost edge line and use inner contour lines. We label four inner contour lines in order among the inner lines, and then we extract left and right eye with known distance relationship and with two eyes coordinates, and calculate slope information. At last, we rotate the tilted image in accordance with slope information and then calculate the ten distance features between element and element. In order to make the system invariant to image scale, we normalize these features with distance between left and righ eye. Experimental results show 88% recognition rate for twenty five face images when tilted degree is considered and 60% recognition rate when tilted degree is not considered.

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A Method of Coupling Expected Patch Log Likelihood and Guided Filtering for Image De-noising

  • Wang, Shunfeng;Xie, Jiacen;Zheng, Yuhui;Wang, Jin;Jiang, Tao
    • Journal of Information Processing Systems
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    • v.14 no.2
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    • pp.552-562
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    • 2018
  • With the advent of the information society, image restoration technology has aroused considerable interest. Guided image filtering is more effective in suppressing noise in homogeneous regions, but its edge-preserving property is poor. As such, the critical part of guided filtering lies in the selection of the guided image. The result of the Expected Patch Log Likelihood (EPLL) method maintains a good structure, but it is easy to produce the ladder effect in homogeneous areas. According to the complementarity of EPLL with guided filtering, we propose a method of coupling EPLL and guided filtering for image de-noising. The EPLL model is adopted to construct the guided image for the guided filtering, which can provide better structural information for the guided filtering. Meanwhile, with the secondary smoothing of guided image filtering in image homogenization areas, we can improve the noise suppression effect in those areas while reducing the ladder effect brought about by the EPLL. The experimental results show that it not only retains the excellent performance of EPLL, but also produces better visual effects and a higher peak signal-to-noise ratio by adopting the proposed method.

An Automatic Mapping Points Extraction Algorithm for Calibration of the Wide Angle Camera (광각 카메라 영상의 보정을 위한 자동 정합 좌표 추출 방법)

  • Kim, Byung-Ik;Kim, Dae-Hyeon;Bae, Tae-Wuk;Kim, Young-Choon;Shim, Tae-Eun;Kim, Duk-Gyoo
    • Journal of Korea Multimedia Society
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    • v.13 no.3
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    • pp.410-416
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    • 2010
  • This paper presents the auto-extraction method that searches for the Mapping points in the calibration algorithm of the image acquired by the wide angle CCD camera. In this algorithm, we remove the noise from the distorted image and then obtain the edge image. Proposed method extracts the distortion point, comparing the threshold value of the histogram of the horizontal and vertical pixel lines in edge image. This processing step can be directly applied to the original image of the wide angle CCD camera output. Proposed method results are compared with hand-worked result image using the two wide angle CCD cameras having different angles with the difference value of the result images respectively. Experimental results show that proposed method can allocate the distortion-calibration constant of the wide angle CCD camera regardless of lens type, distortion shape and image type.

Medical Image Watermarking Using Mallat Wavelet Transform (Mallat 웨이브릿 변환을 이용한 의료 영상 워터마킹)

  • 고창림;조진호
    • Journal of Biomedical Engineering Research
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    • v.23 no.2
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    • pp.81-85
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    • 2002
  • In this paper, a new fragi1e watermarking algorithm for medical images is proposed. It makes possible to resolve the security and forgery problem of the medical images. In the proposed algorithm. the singularity which represents the inherent characteristic of the medical image is extracted and used as watermark. To extract the singularity point. we adopted Mallat wavelet transform because it can describe the edge of image exactly. Mallat wavelet transform produces horizontal and vertical subbands of the same resolution with the original image. The magnitude and phase components of the edge are obtained using these subbands. Based on the magnitude and phase components. LMM which will be used as watermark is determined. As LMM is the inherent singularity of image, if any forgery is applied to medical image, LMM of original and forged image are different each other Detecting the changes of LMM for the two images makes it possible whether any image is undergone forgery or not From the experimental results, we conformed that the proposed algorithm detects the forged area of the image very well.

Character Region Detection Using Structural Features of Hangul Vowel (한글 모음의 구조적 특징을 이용한 문자영역 검출 기법)

  • Park, Jong-Cheon;Lee, Keun-Wang;Park, Hyoung-Keun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.2
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    • pp.872-877
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    • 2012
  • We proposes the method to detect the Hangul character region from natural image using topological structural feature of Hangul grapheme. First, we transform a natural image to a gray-scale image. Second, feature extraction performed with edge and connected component based method, Edge-based method use a Canny-edge detector and connected component based method applied the local range filtering. Next, if features are not corresponding to the heuristic rule of Hangul character, extracted features filtered out and select candidates of character region. Next, candidates of Hangul character region are merged into one Hangul character using Hangul character merging algorithm. Finally, we detect the final character region by Hangul character class decision algorithm. Experimental result, proposed method could detect a character region effectively in images that contains a complex background and various environments. As a result of the performance evaluation, A proposed method showed advanced results about detection of Hangul character region from mobile image.