1CONVERSIONS(3)             Library Functions Manual             CONVERSIONS(3)
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NAME

6       im_c2amph,  im_c2imag,  im_c2ps, im_c2real, im_clip2fmt, im_ri2c - con‐
7       version between image types
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SYNOPSIS

10       #include <vips/vips.h>
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12       int im_c2amph(in, out)
13       IMAGE *in, *out;
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15       int im_c2rect(in, out)
16       IMAGE *in, *out;
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18       int im_c2imag(in, out)
19       IMAGE *in, *out;
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21       int im_c2ps(in, out)
22       IMAGE *in, *out;
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24       int im_c2real(in, out)
25       IMAGE *in, *out;
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27       int im_clip2fmt(in, out, ofmt)
28       IMAGE *in, *out;
29       int ofmt;
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31       int im_ri2c(in1, in2, out)
32       IMAGE *in1, *in2, *out;
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DESCRIPTION

35       Each of the above functions  converts  the  image  held  by  the  image
36       descriptor  in to another type image and writes the result on the image
37       descriptor out.  Sizes and the number  of  channels  are  identical  to
38       those  of input.  Whenever required by the conversion, the element val‐
39       ues are rounded by calling floor().
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41       im_c2amph() converts a complex (float or double) input  to  (amplitude,
42       phase), with phase in degrees.  Output has the same format as input.
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44       im_c2rect()  converts  a complex (float or double) input in (amplitude,
45       phase) form back to rectangular coordinates.  Again,  phase  should  be
46       expressed in degrees.
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48       im_c2ps() convert a (float or double) complex image to amplitude (float
49       or double) image.  Complex input (a,b) is mapped to sqrt( a*a+b*b ).
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51       im_clip2fmt() converts the input image to 'ofmt', where ofmt is the new
52       value  for  BandFmt.  For example, im_clip2fmt(in, out, FMTUSHORT) con‐
53       verts any image to unsigned short.
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55       The number of clipped values (if any),  are  printed  in  the  standard
56       error  output.  Before  clipping  rounding is carried out if necessary.
57       When converting between real and complex types  with  these  functions,
58       the  imaginary  part of the output is set to zero. When converting from
59       complex to real types, the imaginary part is  ignored.  Use  im_c2ps(),
60       im_c2real() etc. to get other behaviour.
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62       Legacy   functions   are   available,  called  im_clip(),  im_clip2c(),
63       im_clip2d(),  im_clip2f(),  im_clip2i(),   im_clip2s(),   im_clip2ui(),
64       im_clip2us(),  im_clip2cm()  and  im_clip2dcm() which convert the input
65       image to  unsigned  char,  signed  char,  double,  float,  int,  short,
66       unsigned int, unsigned short, complex and double complex respectively.
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68       im_ri2c()  takes  as  inputs  two non-complex images of equal sizes and
69       number of channels.  The output is a complex image with the  real  part
70       coming  from  in1  and  the  imaginary part coming from in2.  Output is
71       float complex (FMTCOMPLEX) only if none of the inputs  is  double.   If
72       one  or  both inputs are double the result is double complex (FMTDPCOM‐
73       PLEX).
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75       im_c2real() and im_c2imag() extract the real or the imaginary part of a
76       complex  image  respectively.   If  input is be float complex or double
77       complex, then output is float or double respectively.
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RETURN VALUE

81       The functions returns 0 on success and -1 on error.
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SEE ALSO

84       im_scale(3).
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88                                 15 April 1991                  CONVERSIONS(3)
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