59 lines
1.6 KiB
Groff
59 lines
1.6 KiB
Groff
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.TH IM_AFFINEI 3 "8 February 2009"
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.SH NAME
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im_affinei \- apply an affine transform to an image
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.SH SYNOPSIS
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.B #include <vips/vips.h>
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int im_affinei(in, out, interpolate, a, b, c, d, dx, dy, x, y, w, h)
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.br
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.B IMAGE *in, *out;
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.br
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.B VipsInterpolate *interpolate;
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.br
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.B double a, b, c, d, dx, dy;
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.br
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.B int x, y;
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.br
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.B int w, h;
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int im_affinei_all(in, out, interpolate, a, b, c, d, dx, dy)
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.br
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.B IMAGE *in, *out;
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.br
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.B VipsInterpolate *interpolate;
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.br
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.B double a, b, c, d, dx, dy;
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.SH DESCRIPTION
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.B im_affinei()
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applies an affine transformation on the image held by the IMAGE descriptor
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in and puts the result at the location pointed by the IMAGE descriptor out. in
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many have any number of bands, be any size, and have any non-complex type.
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The transformation is described by a, b, c, d, dx, dy. The point (x,y) in
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the input is mapped onto point (X,Y) in the output by
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X = a * x + b * y + dx
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Y = c * x + d * y + dy
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The area of the output image given by w, h, x, y is generated. (0,0) is
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the position of the transformed top-left-hand corner of the input image.
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Points are generated using the supplied interpolator. See
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.B VipsInterpolate(3)
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for a list of the interpolators that come with vips.
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.B im_affinei_all(3)
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is a convenience function that transforms the whole of the input image. It
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calls
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.B im_affine(3)
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for you, with x y w h set to exactly enclose the transformed image.
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.SH RETURN VALUE
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The functions return 0 on success and -1 on error.
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.SH BUGS
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As with most resamplers, im_affine(3) performs poorly at the edges of
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images.
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.SH SEE ALSO
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im_similarity(3)
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