| Image Processing Toolbox | |
Convert point-spread function to optical transfer function.
Syntax
Description
OTF = psf2otf(PSF) computes the Fast Fourier Transform (FFT) of the point-spread function (PSF) array and creates the optical transfer function array, OTF, that is not influenced by the PSF off-centering. By default, the OTF array is the same size as the PSF array.
OTF = psf2otf(PSF,OUTSIZE) converts the PSF array into an OTF array, where OUTSIZE specifies the size of the OTF array. The OUTSIZE cannot be smaller than the PSF array size in any dimension.
To ensure that the OTF is not altered due to PSF off-centering, psf2otf post-pads the PSF array (down or to the right) with zeros to match dimensions specified in OUTSIZE, then circularly shifts the values of the PSF array up (or to the left) until the central pixel reaches (1,1) position.
Note that this function is used in image convolution/deconvolution when the operations involve the FFT.
Class Support
PSF can be any nonsparse, numeric array. OTF is of class double.
Example
PSF = fspecial('gaussian',13,1); OTF = psf2otf(PSF,[31 31]); % PSF --> OTF subplot(1,2,1); surf(PSF); title('PSF'); axis square; axis tight subplot(1,2,2); surf(abs(OTF)); title('corresponding |OTF|'); axis square; axis tight
See Also
| | pixval | qtdecomp | |