ITERATIVE, CONSTRAINED 3-D IMAGE-RECONSTRUCTION OF TRANSMITTED LIGHT BRIGHT-FIELD MICROGRAPHS BASED ON MAXIMUM-LIKELIHOOD-ESTIMATION

We present several image reconstruction algorithms for generating thre e-dimensional (3-D) renderings of bright-field micrographs that are fo unded on maximum likelihood estimation (MLE) theory. The basic princip le of the algorithms is in estimating the values of the optical densit ies of the specimen. A computer simulation and initial experimental te sting of a steepest ascent version of the algorithm is presented. The computer simulation demonstrates that the MLE algorithm has an advanta ge over previously used inverse filtering techniques in that it partia lly restores the zeroed Fourier components in the well-known missing-c one region. We present 3-D reconstructions from real biological data t o show the potential of the algorithm in practical applications.