Journal of South China University of Technology (Natural Science Edition) ›› 2010, Vol. 38 ›› Issue (6): 118-121,133.doi: 10.3969/j.issn.1000-565X.2010.06.022

• Mechanical Engineering • Previous Articles     Next Articles

PSF Estimation and Edge Detection of Defocused Noisy Image

Wu Jun-fang  Liu Gui-xiong  Wei Ning   

  1. School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China
  • Received:2009-07-31 Revised:2009-09-21 Online:2010-06-25 Published:2010-06-25
  • Contact: 吴俊芳（1977-），女，讲师，博士生，主要从事现代检测技术及应用研究． E-mail:wujf@scut．edu．cn
  • About author:吴俊芳（1977-），女，讲师，博士生，主要从事现代检测技术及应用研究．
  • Supported by:

    国家自然科学基金资助项目（50805053）

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Abstract:

By considering the causes of image blur in machine vision,the point spread function（PSF） is described with the generalized Gaussian function,and an blurred edge model is established.Then,some samples are obtained from the edges of an image.Moreover,an integration rule is proposed to calculate the PSF of the image according to the estimated results of all the samples.Finally,the optimal PSF and sub-pixel level edge position are estimated via the least squares approximation.Experimental results show that the proposed edge detection algorithm is robust to noise due to the accurate estimation of PSF,and that the dimension error based on the sub-pixel-level edge detection is less than 0.5%.

Key words: image processing, edge detection, point spread function, least squares approximations, sub-pixel