fft_inv__ ( Image : ImageFFTInv : : )

Compute the inverse fast Fourier transform of an image.

fft_inv__ calculates the inverse Fourier transform of the input image (Image), i.e., it transforms the image back into the spatial domain. This corresponds to the call

     fft_generic(Image:ImageFFT:'from_freq',-1,'sqrt','dc_center':) >
     convert_image_type__(ImageFFT:ImageFFTInv:'byte':) .
The result image is of type 'byte'.


Attention

The filtering is always done on the entire image, i.e., the region of the image is ignored. The images must be quadratic and the width and height must be a power of 2.


Parameters

Image (input_object)
image(-array) -> object : complex
Input image.

ImageFFTInv (output_object)
image(-array) -> object : byte
Inverse-Fourier-transformed image.


Example
fft__(Image,&FFT);
gen_gabor(&Filter,1.4,0.4,1.0,1.5,512);
convol_gabor__(FFT,Filter,&Gabor,&Hilbert);
fft_inv__(Gabor,&GaborInv);
fft_inv__(Hilbert,&HilbertInv);
energy__(GaborInv,HilbertInv,&Energy);

Result

fft_inv__ returns TRUE if the input image is of correct type and its width and height are a power of 2. If the input is empty the behaviour can be set via set_system(::'no_object_result',<Result>:). If necessary, an exception is raised.


Possible Predecessors

convol_fft__, convol_gabor__, fft__


Possible Successors

convert_image_type__, energy__


Alternatives

fft_generic


See also

fft__, fft_generic, energy__



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