im_freqflt - filters an image with a float filter mask in the frequency
int im_freqflt(in, filtermask, out)
IMAGE *in, *filtermask, *out;
im_freqflt() performs filtering in the frequency domain of the input
image held by the image descriptor in with a mask held by the
descriptor filtermask and writes the result on the image descriptor
Image sizes should be power of two and less or equal to 512. All
images should be one channel square images. Image filtermask is a non-
complex one channel image created by im_create_fmask(). Input image
can be any type. If input is complex, in and filtermask are multiplied
using the function im_cmultim(3).
If input is not complex then it is transformed into the frequency
domain and then it is multiplied with the filtermask. In the latter
case the result is inverse fourier transformed and clipped to the input
image format using the function im_clip2fmt(3).
The function returns 0 on success and -1 on error.
The function has not been fully tested.
im_fwfft(3), im_invfft(3), im_create_fmask(3), im_cmultim(3).
N. Dessipris - 10/05/1991
10 May 1991 IM_FOURFLT(3)