Correlation-based methods of automatic particle detection in electron microscopy images with smoothing by anisotropic diffusion

Authors

  • W. V. Nicholson,

    Corresponding author
    1. School of Biomedical Sciences, University of Leeds, Worsley Building, Leeds LS2 9JT, U.K.
    Search for more papers by this author
  • R. Malladi

    1. School of Biomedical Sciences, University of Leeds, Worsley Building, Leeds LS2 9JT, U.K.
    2. Computing Science Department, University of California, Berkeley, CA 94720, U.S.A.
    Search for more papers by this author

William V. Nicholson. Tel.: +44 (0)113 343 3034; e-mail: william_v_nicholson@yahoo.com

Summary

Two methods of correlation-based automatic particle detection in electron microscopy images are compared – computing a cross-correlation function or a local correlation coefficient vs. azimuthally averaged reference projections (either from a model or from experimental particle images). The ability of smoothing images by anisotropic diffusion to improve the performance of particle detection is also considered. Anisotropic diffusion is an effective method of preprocessing that enhances the edges and overall shape of particles while reducing noise. It is found that anisotropic diffusion improves particle detection by a local correlation coefficient when projections from a high-resolution reconstruction are used as references. When references from experimental particle images are used, a cross-correlation function shows a more marked improvement in particle detection in images smoothed by anisotropic diffusion.

Ancillary