42 lines
1.4 KiB
Groff
42 lines
1.4 KiB
Groff
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.TH SUBTRACTION 3 "24 April 1991"
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.SH NAME
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im_subtract \- subtracts two images
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.SH SYNOPSIS
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#include <vips/vips.h>
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int im_subtract(in1, in2, out)
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.br
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IMAGE *in1, *in2, *out;
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.SH DESCRIPTION
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This functions calculates in1 - in2 and writes the result in the image
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descriptor out. Input images in1 and in2 should have the same channels and
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the same sizes; however they can be of different types. Only the history of
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the image descriptor pointed by in1 is copied to out.
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The type of the output is given by the table:
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in1 - uchar char ushort short uint int
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-------|-----------------------------------------
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in2 |
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uchar | short short short short int int
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char | short short short short int int
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ushort | short short short short int int
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short | short short short short int int
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uint | int int int int int int
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int | int int int int int int
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The result of this operation cannot be unsigned. For float types, the refult
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is float unless one of the inputs is double, in which case the result is
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double. For complex types the result is FMTCOMPLEX, unless one of the inputs
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is FMTDPCOMPLEX, in which case the output is FMTDPCOMPLEX.
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.SH BUGS
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None of the functions checks the result for over/underflow.
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.SH RETURN VALUE
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All functions return 0 on success and -1 on error.
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.SH SEE ALSO
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im_add(3), im_lintra(3), im_multiply(3).
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.SH COPYRIGHT
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National Gallery, 1995
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