Reconstruction from Microscopic Projections with Defocus-Gradient and Attenuation Effects

We discuss and illustrate defocus-gradient and attenuation effects that are part of the image formation models of microscopy of biological specimens. We demonstrate how they affect the projection data and in turn the 3D reconstructions. Biologically meaningful results can be obtained ignoring both of these effects, but using image processing techniques to incorporate corrections for them into reconstruction methods provides more accurate reconstructions, with potential for creating higher-resolution models of the biological specimens.