1IM_DISP_PS(3) Library Functions Manual IM_DISP_PS(3)
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6 im_disp_ps - creates a displayable power spectrum of an one band image
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9 #include <vips/vips.h>
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11 int im_disp_ps(in, out)
12 IMAGE *in, *out;
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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.
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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)).
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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.
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31 The function returns 0 on success and -1 on error.
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34 im_fwfft(3), im_c2ps(3), im_scaleps(3), im_rotquad(3).
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37 N. Dessipris
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40 N. Dessipris - 23/05/1991
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44 23 May 1991 IM_DISP_PS(3)