Tomography of Large Format Electron Microscope Tilt Series: Image Alignment and Volume Reconstruction

Image alignment is a critical step in obtaining high quality reconstructions. Bundle adjustment, based on a general projective model, combined with calculation of the envelope of backprojected tangents to a surface of revolution around the rotation axis establish the parameters of the projection maps, rotation angles and axis of rotation. Subsequent regression techniques may be used to calculate higher order polynomial corrections to the projection maps, and can compensate for curvilinear trajectories through the object, sample warping, and optical aberration. Backprojection from properly filtered images along the nominal electron trajectories yields high quality 3D reconstructions. We report here on recent extensions to the electron microscope tomography code, TxBR. In addition we discuss the basis for this code in the theory of Fourier integral operators.