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im_disp_ps - creates a displayable power spectrum of an one band image
#include <vips/vips.h>
int im_disp_ps(in, out)
IMAGE *in, *out;
im_disp_ps() creates a displayable power spectrum
of the image held by the image descriptor in. The resultant unsigned char
image is written on the image descriptor out. Input should be one band
image of any non-complex type.
The function finds the fourier transform
of the input (if in is not complex) and then the amplitude power spectrum
is created (im_c2ps(3X)
). The power spectrum is passed through a non-linear
transformation (im_scaleps(3X)
). The final image has the four quadrants
rotated in such a way that the coordinate (0,0) is near the centre of the
image (im_rotquad(3X)
).
Input should be a square image with size power
of 2. The maximum size of the input image is dictated by the available RAM.
The function returns 0 on success and -1 on error.
im_fwfft(3X)
,
im_c2ps(3X)
, im_scaleps(3X)
, im_rotquad(3X)
, im_mmapin(3X)
, im_openout(3X)
,
im_setbuf(3X)
.
N. Dessipris
N. Dessipris - 23/05/1991
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