3D Reconstruction: Backprojection

Outline of the 3D reconfiguration method

There are several methods usable for 3D reconfiguration. The methods marked with Eos are the ones supported by Eos. 1. Simple Backward projection (Eos): Used to perform backward projection simply. 2. Weighted backward projection (Eos): Used to give weight in the Fourier space based on the projection angle of the projected image. This method is often used when a low-pass filter is applied to one-axis projection (tomography). 3. Backward projection with a filter (not supported yet) 4. Iterative method 4.1 SIRT method (Simultaneous Iterative Reconstruction Technique) 4.2 ART method (Algebric Iterative Reconstruction Technique) (not supported yet) 5. Radon transformation method (Eos)

In the exercise, the weighted backward projection method is used.

IX-2. Practice of the 3D reconstruction A program to perform the 3D reconfiguration method utilizing the weighted backward projection is as follows:

.3dlst.3d: 
	mrc2Dto3D -I $(TARGET).3dlst -o $(TARGET).3d -InterpolationMode 2 -Double -DoubleCounter $(TARGET).3dcounter -CounterThreshold 0.5 -m 1 -WeightMode 2 

“$(TARGET).3dcounter” shows weight. If $(TARGET).3d and $(TARGET).3dcounter files are available, 3D images can be averaged using mrcImageAverage.