Wavelet multi-resolution of electron microscopic image. An electron cryomicroscopy image contains 5 particle images of the herpes simplex virus B-capsid. Two particles are circled for identification. The imaging conditions emphasize high resolution information which allows the determination of high resolution three-dimensional reconstructions. However, the effect on the image is the appearance of a very low contrast image which makes both particle selection and processing difficult. The image shown is only a small region of the image. The images currently obtained are in the order of 9000 × 13000 pixels and occupy from 100 to 300 megabytes. (b) wavelet approximation at level one of (a). (c) Fourier-filtered and sub-sampled by a factor of two in each direction of the image in (a).