• Title/Summary/Keyword: 에지 보존

Search Result 131, Processing Time 0.025 seconds

Building Roof Reconstruction in Remote Sensing Image using Line Segment Extraction and Grouping (선소의 추출과 그룹화를 이용한 원격탐사영상에서 건물 지붕의 복원)

  • 예철수;전승헌;이호영;이쾌희
    • Korean Journal of Remote Sensing
    • /
    • v.19 no.2
    • /
    • pp.159-169
    • /
    • 2003
  • This paper presents a method for automatic 3-d building reconstruction using high resolution aerial imagery. First, by using edge preserving filtering, noise is eliminated and then images are segmented by watershed algorithm, which preserves location of edge pixels. To extract line segments between control points from boundary of each region, we calculate curvature of each pixel on the boundary and then find the control points. Line segment linking is performed according to direction and length of line segments and the location of line segments is adjusted using gradient magnitudes of all pixels of the line segment. Coplanar grouping and pplygonal patch formation are performed per region by selecting 3-d line segments that are matched using epipolar geometry and flight information. The algorithm has been applied to high resolution aerial images and the results show accurate 3D building reconstruction.

Efficient Single Image Dehazing by Pixel-based JBDCP and Low Complexity Transmission Estimation (저 복잡도 전달량 추정 및 픽셀 기반 JBDCP에 의한 효율적인 단일 영상 안개 제거 방법)

  • Kim, Jong-Ho
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.14 no.5
    • /
    • pp.977-984
    • /
    • 2019
  • This paper proposes a single image dehazing that utilizes the transmission estimation with low complexity and the pixel-based JBDCP (Joint Bright and Dark Channel Prior) for the effective application of hazy outdoor images. The conventional transmission estimation includes the refinement process with high computational complexity and memory requirements. We propose the transmission estimation using combination of pixel- and block-based dark channel information and it significantly reduces the complexity while preserving the edge information accurately. Moreover, it is possible to estimate the transmission reflecting the image characteristics, by obtaining a different air-light for each pixel position of the image using the pixel-based JBDCP. Experimental results on various hazy images illustrate that the proposed method exhibits excellent dehazing performance with low complexity compared to the conventional methods; thus, it can be applied in various fields including real-time devices.

Image Restoration Filter for Preserving High Frequency Components in Impulse Noise Environments (임펄스 잡음 환경에서 고주파 성분을 보존하기 위한 영상 복원 필터)

  • Cheon, Bong-Won;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.23 no.4
    • /
    • pp.394-400
    • /
    • 2019
  • Noise removal is one of the required step in processing digital video and there are many researches to develop algorithm that fits with its purpose and environment. However, present impulse noise removal methods are lacking in its function in terms of removing noise in edge and high frequency factors. Therefore, this research has Extended range of masks depending on density to determine noise so that high frequency factors can be preserved. The range of resolution is set based on median and standard deviation of inside resolution after removing impulse noise. afterwards, those resolution within the range are calculated by adding weight to have the final output value. The suggested algorithm has an enhanced function in removing noise in various areas with many edge and high frequency factors than present methods and their functions are compared through simulation.

Modified Median Filter for Impulse Noise Removal (임펄스 잡음 제거를 위한 변형된 메디안 필터)

  • Long, Xu;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.17 no.2
    • /
    • pp.461-466
    • /
    • 2013
  • As the technology of the digital information age has developed rapidly, lots of research has been done on the digital image processing techniques, such as the image restoration. However, the SM(Standard Median) filter is a typical method of recovering the image which are corrupted by the impulse noise, this method will also reduce the quality of image by generating an error in the edge region. In this paper, in order to restore the corrupted images in the impulse noise environment, a modified median filter algorithm is proposed, which uses the pixels as the center and takes double mask. By using the double mask, we are succeeded in acquiring the excellent performance on noise-canceling, edge preservation, and also in improving the quality of image.

A Study on Image Restoration using Mean and Wiener Filter (평균 및 위너 필터를 사용한 영상 복원에 관한 연구)

  • Moon Hong-Deuk;Kang Kyeong-Deog;Bae Sang-Bum;Kim Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.8 no.7
    • /
    • pp.1393-1398
    • /
    • 2004
  • Image is degraded by several causes such as the process of acquisition, storage and transmission. To restore those images, many researches have been continued. Centrally methods to restore degraded image by AWGN(additive white gaussian noise) a.e mean filter and wiener filter. Especially, mean filter is superior in noise reduction of area that is a small change of luminosity. But mean filter brings about the effect smoothing edge components of the image, because it does'nt consider characteristics of the image. So in this paper we propose an image restoration method compounding respective images adding established weights, after filtering with mean filter and powerful wiener filter in both improvement of contrast and preservation of edge components.

A Potts Automata algorithm for Noise Removal and Edge Detection (Potts Automata를 이용한 영상의 잡음 제거 및 에지 주줄)

  • 이석기;김석태;조성진
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.28 no.3C
    • /
    • pp.327-335
    • /
    • 2003
  • Cellular Automata is discrete dynamical systems which natural phenomena may be specified completely in terms of local relation. In this Paper we Propose noise removal and edge detection algorithm using a Potts Automata which is based on Cellular Automata. The proposed method is aimed to locally increase or decrease the differences in gray level values between pixel of the image without loss of the main characteristics of the image. The dynamical behavior of these automata is determined by Lyapunov operators for sequential and parallel update. We have found that proposed automata rules Present very fast convergence to fixed points, stability in front of random noisy images. Based on the experimental results we discuses the advantage and efficiency.

A Study on Noise Reduction Method using Wavelet Approximation Coefficient-based Distribution Characteristics (웨이브렛 근사계수 기반의 분포특성을 이용한 잡음 제거 방법에 관한 연구)

  • Bae, Sang-Bum;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.14 no.2
    • /
    • pp.513-520
    • /
    • 2010
  • The degradation phenomenon caused by noises significantly corrupts digitalized data. Therefore, a variety of methods to preserve the edge component of signals and remove noise simultaneously have been used in time domain and frequency domain. In this paper, we have proposed a new noise reduction algorithm using wavelet approximation coefficients to reduce the mixed noise overlapping the signal. The proposed algorithm adopts the distribution characteristics of the error function which is obtained by accumulating the wavelet approximation coefficients, in order to improve the capability to separate edges of the signal and noises.

Feature Point Extraction of Sea Cucumbers using Canny Edge Detection (캐니 에지 검출을 이용한 해삼의 특징점 추출)

  • Lee, Keon-Ik;Woo, Young-Bae;Min, Jun-Sik;Choi, Chul-Jae
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.13 no.6
    • /
    • pp.1281-1286
    • /
    • 2018
  • The sea cucumber, which is distributed over 1,500 species worldwide, is a highly value-added variety that has been considered an important source of marine resources in many countries for a long period of time. Most of the research on sea cucumbers involves the effectiveness of food and its extractions; however, there was no research on the extraction of sea cucumbers. In response, this research suggested a boundary detection algorithm to extract the special spot of sea cucumbers Therefore, in order to capture a large quantity of high value-added in sea cucumbers and we believe that they will be a great help to the sea cucumber recognition program in the future.

A Study on Image Restoration for Removing Mixed Noise while Considering Edge Information (에지정보를 고려한 복합잡음 제거를 위한 영상복원에 관한 연구)

  • Gao, Yinyu;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.15 no.10
    • /
    • pp.2239-2246
    • /
    • 2011
  • In image signal processing, image signal is corrupted by various noises and caused the degradation phenomenon. And Images often corrupted by AWGN(additive white gaussian noise) and impulse noise which called mixed noise. In this paper, the algorithm is proposed to remove mixed noise while keeping edge information. The proposed algorithm first classifies the noise type, if the classify result is AWGN, then the mean of the output after using self-adaptive weighted mean filter and median value will be the outfiltering value. And if the noise type is impulse noise, then the noise is removed by a modified nonlinear filter. Also we compare existing methods through the simulation and using PSNR(peak signal to noise ratio) as the standard of judgement of improvement effect. The result of computer simulation on test images indicates that the proposed method is superior to traditional filtering algorithms.

A Study on the Pixel-Parallel Usage Processing Using the Format Converter (포맷 변환기를 이용한 화소-병렬 화상처리에 관한 연구)

  • Kim, Hyeon-Gi;Lee, Cheon-Hui
    • The KIPS Transactions:PartA
    • /
    • v.9A no.2
    • /
    • pp.259-266
    • /
    • 2002
  • In this paper we implemented various image processing filtering using the format converter. This design method is based on realized the large processor-per-pixel array by integrated circuit technology. These two types of integrated structure are can be classify associative parallel processor and parallel process DRAM (or SRAM) cell. Layout pitch of one-bit-wide logic is Identical memory cell pitch to array high density PEs in integrate structure. This format converter design has control path implementation efficiently, and can be utilize the high technology without complicated controller hardware. Sequence of array instruction are generated by host computer before process start, and instructions are saved on unit controller. Host computer is executed the pixel-parallel operation starting at saved instructions after processing start. As a result, we obtained three result that 1) simple smoothing suppresses higher spatial frequencies, reducing noise but also blurring edges, 2) a smoothing and segmentation process reduces noise while preserving sharp edges, and 3) median filtering may be applied to reduce image noise. Median filtering eliminates spikes while maintaining sharp edges and preserving monotonic variations in pixel values.