33 lines
1.1 KiB
Groff
33 lines
1.1 KiB
Groff
.TH IM_DISP_PS 3 "23 May 1991"
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.SH NAME
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im_disp_ps \- creates a displayable power spectrum of an one band image
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.SH SYNOPSIS
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.B #include <vips/vips.h>
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.B int im_disp_ps(in, out)
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.br
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.B IMAGE *in, *out;
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.SH DESCRIPTION
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im_disp_ps() creates a displayable power spectrum of the image held by the
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image descriptor in. The resultant unsigned char image is written on the
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image descriptor out. Input should be one band image of any non-complex
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type.
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The function finds the fourier transform of the input (if in is not complex)
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and then the amplitude power spectrum is created (im_c2ps(3)). The power
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spectrum is passed through a non-linear transformation (im_scaleps(3)). The
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final image has the four quadrants rotated in such a way that the coordinate
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(0,0) is near the centre of the image (im_rotquad(3)).
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Input should be a square image with size power of 2.
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The maximum size of the input image is dictated by the available RAM.
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.SH RETURN VALUE
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The function returns 0 on success and -1 on error.
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.SH SEE ALSO
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im_fwfft(3), im_c2ps(3), im_scaleps(3), im_rotquad(3).
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.SH COPYRIGHT
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.br
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N. Dessipris
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.SH AUTHOR
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N. Dessipris \- 23/05/1991
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