fft_image

Herror ::fft_image_inv ( Hobject Image, Hobject *ImageFFTInv ) HImage HImage::FftImageInv ( void ) const HImageArray HImageArray::FftImageInv ( void ) const

Compute the inverse fast Fourier transform of an image.

::fft_image_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) `->` Hobject: HImage(Array) ( complex )
Input image.

`ImageFFTInv` (output_object)	image(-array) `->` Hobject : HImage(Array)* ( byte )
Inverse-Fourier-transformed image.

Example

fft_image(Image,&FFT);
gen_gabor(&Filter,1.4,0.4,1.0,1.5,512);
convol_gabor(FFT,Filter,&Gabor,&Hilbert);
fft_image_inv(Gabor,&GaborInv);
fft_image_inv(Hilbert,&HilbertInv);
energy_gabor(GaborInv,HilbertInv,&Energy);

Result

::fft_image_inv returns H_MSG_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 handling is raised.

Possible Predecessors

::convol_fft, ::convol_gabor, ::fft_image

Possible Successors

::convert_image_type, ::energy_gabor

Alternatives

::fft_generic

Module

Image filters