Image Processing Toolbox User's Guide

Fan-Beam Projection Data

The fanbeam function in the Image Processing Toolbox computes projections of an image matrix along specified directions. A projection of a two-dimensional function f(x,y) is a set of line integrals. The fanbeam function computes the line integrals along paths that radiate from a single source, forming a fan shape. To represent an image, the fanbeam function takes multiple projections of the image from different angles by rotating the source around the center of the image. The following figure shows a single fan-beam projection at a specified rotation angle.

Fan-Beam Projection at Rotation Angle Theta

This section

• Describes how to use the fanbeam function to generate fan-beam projection data
• Describes how to reconstruct an image from fan-beam projection data
• Shows an example that creates a fan-beam projection of an image and then reconstructs the image from the fan-beam projection data

Note    For information about creating projection data from line integrals along parallel paths, see Radon Transform. To convert fan-beam projection data to parallel-beam projection data, use the fan2para function.

Example: Reconstructing an Image from Parallel Projection Data

Computing Fan-Beam Projection Data

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