# iradon

Inverse Radon transform

## Syntax

## Description

specifies additional parameters to use in the inverse Radon transform. You can
specify any combination of the last four arguments. To omit an argument, specify
the value as an empty array (`I`

= iradon(`R`

,`theta`

,`interp`

,`filter`

,`frequencyScaling`

,`outputSize`

)`[]`

).`iradon`

uses default values for arguments that you omit.

## Examples

## Input Arguments

## Output Arguments

## Algorithms

`iradon`

assumes that the center of rotation is the center point of
the projections, which is defined as `ceil(size(R,1)/2)`

.

`iradon`

uses the filtered back projection algorithm to perform the
inverse Radon transform. The filter is designed directly in the frequency domain and
then multiplied by the FFT of the projections. The projections are zero-padded to a
power of 2 before filtering to prevent spatial domain aliasing and to speed up the
FFT.

## References

[1] Kak, A. C., and M. Slaney, *Principles of
Computerized Tomographic Imaging*, New York, NY, IEEE Press,
1988.

## Extended Capabilities

## Version History

**Introduced before R2006a**