Image Processing Toolbox User's Guide 
FanBeam Projection Data
The fanbeam
function in the Image Processing Toolbox computes projections of an image matrix along specified directions. A projection of a twodimensional 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 fanbeam projection at a specified rotation angle.
FanBeam Projection at Rotation Angle Theta
fanbeam
function to generate fanbeam projection data
Note
For information about creating projection data from line integrals along parallel paths, see Radon Transform. To convert fanbeam projection data to parallelbeam projection data, use the fan2para function.

Example: Reconstructing an Image from Parallel Projection Data  Computing FanBeam Projection Data 
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