| .TH IM_FOURFLT 3 "10 May 1991" |
| .SH NAME |
| im_freqflt \- filters an image with a float filter mask in the frequency domain |
| .SH SYNOPSIS |
| .B #include <vips/vips.h> |
| |
| .B int im_freqflt(in, filtermask, out) |
| .br |
| IMAGE *in, *filtermask, *out; |
| .SH DESCRIPTION |
| 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 out. |
| |
| 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). |
| .SH RETURN VALUE |
| The function returns 0 on success and -1 on error. |
| .SH BUGS |
| The function has not been fully tested. |
| .SH SEE\ ALSO |
| im_fwfft(3), im_invfft(3), im_create_fmask(3), im_cmultim(3). |
| .SH COPYRIGHT |
| .br |
| N. Dessipris |
| .SH AUTHOR |
| N. Dessipris \- 10/05/1991 |
