libvips/include/vips/transform.h

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2008-11-17 23:56:16 +01:00
/* Affine transforms.
*/
/*
Copyright (C) 1991-2003 The National Gallery
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
/* Params for an affine transformation.
*/
typedef struct {
/* Area of input we can use. This can be smaller than the real input
* image: we expand the input to add extra pixels for interpolation.
*/
Rect iarea;
/* The area of the output we've been asked to generate. left/top can
* be negative.
*/
Rect oarea;
/* The transform.
*/
double a, b, c, d;
double dx, dy;
double ia, ib, ic, id; /* Inverse of matrix abcd */
} Transformation;
void im__transform_init( Transformation *trn );
int im__transform_calc_inverse( Transformation *trn );
int im__transform_isidentity( const Transformation *trn );
int im__transform_add( const Transformation *in1, const Transformation *in2,
Transformation *out );
void im__transform_print( const Transformation *trn );
void im__transform_forward_point( const Transformation *trn,
const double x, const double y, double *ox, double *oy );
void im__transform_invert_point( const Transformation *trn,
const double x, const double y, double *ox, double *oy );
void im__transform_forward_rect( const Transformation *trn,
const Rect *in, Rect *out );
void im__transform_invert_rect( const Transformation *trn,
const Rect *in, Rect *out );
void im__transform_set_area( Transformation * );
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int im__affine( IMAGE *in, IMAGE *out, Transformation *trn );