1IM_DISP_PS(3)              Library Functions Manual              IM_DISP_PS(3)
2
3
4

NAME

6       im_disp_ps - creates a displayable power spectrum of an one band image
7

SYNOPSIS

9       #include <vips/vips.h>
10
11       int im_disp_ps(in, out)
12       IMAGE *in, *out;
13

DESCRIPTION

15       im_disp_ps()  creates a displayable power spectrum of the image held by
16       the image descriptor in.  The resultant unsigned char image is  written
17       on  the  image  descriptor  out.  Input should be one band image of any
18       non-complex type.
19
20       The function finds the fourier transform of the input  (if  in  is  not
21       complex) and then the amplitude power spectrum is created (im_c2ps(3)).
22       The power  spectrum  is  passed  through  a  non-linear  transformation
23       (im_scaleps(3)).   The  final  image  has the four quadrants rotated in
24       such a way that the coordinate (0,0) is near the centre  of  the  image
25       (im_rotquad(3)).
26
27       Input  should be a square image with size power of 2.  The maximum size
28       of the input image is dictated by the available RAM.
29

RETURN VALUE

31       The function returns 0 on success and -1 on error.
32

SEE ALSO

34       im_fwfft(3), im_c2ps(3), im_scaleps(3), im_rotquad(3).
35

37       N. Dessipris
38

AUTHOR

40       N. Dessipris - 23/05/1991
41
42
43
44                                  23 May 1991                    IM_DISP_PS(3)
Impressum