39 lines
807 B
Groff
39 lines
807 B
Groff
.TH IM_ZONE 3 "10 May 1991"
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.SH NAME
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im_zone, im_fzone \- creates a zone plate
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.SH SYNOPSIS
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.B #include <vips/vips.h>
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.B int im_zone(image, size)
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.br
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.B IMAGE *image;
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.br
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.B int size;
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.B int im_fzone(image, size)
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.br
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.B IMAGE *image;
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.br
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.B int size;
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.SH DESCRIPTION
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.B im_fzone()
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creates a float one band image of a zone plate of size size by size. Pels are
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in the range [-1,+1]. The zone plate has spatial frequencies increasing from
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0 the center (at size/2, size/2) up to infinity at the edges. size must be
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positive and even.
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.B im_zone()
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behaves exactly as im_fzone(), but writes a FMTUCHAR image scaled to the range
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0-255.
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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_grey(3), im_fgrey(3).
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.SH COPYRIGHT
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N. Dessipris
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.SH AUTHOR
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N. Dessipris \- 10/05/1991
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