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libvips/libsrc/mosaicing/im_affinei.c
John Cupitt 4eb1d6aaf4 stuff
2008-10-20 17:10:40 +00:00

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/* @(#) im_affine() ... affine transform with a supplied interpolator.
* @(#)
* @(#) int im_affinei(in, out, interpolate, a, b, c, d, dx, dy, w, h, x, y)
* @(#)
* @(#) IMAGE *in, *out;
* @(#) VipsInterpolate *interpolate;
* @(#) double a, b, c, d, dx, dy;
* @(#) int w, h, x, y;
* @(#)
* @(#) Forward transform
* @(#) X = a * x + b * y + dx
* @(#) Y = c * x + d * y + dy
* @(#)
* @(#) x and y are the coordinates in input image.
* @(#) X and Y are the coordinates in output image.
* @(#) (0,0) is the upper left corner.
*
* Copyright N. Dessipris
* Written on: 01/11/1991
* Modified on: 12/3/92 JC
* - rounding error in interpolation routine fixed
* - test for scale=1, angle=0 case fixed
* - clipping of output removed: redundant
* - various little tidies
* - problems remain with scale>20, size<10
*
* Re-written on: 20/08/92, J.Ph Laurent
*
* 21/02/93, JC
* - speed-ups
* - simplifications
* - im_similarity now calculates a window and calls this routine
* 6/7/93 JC
* - rewritten for partials
* - ANSIfied
* - now rotates any non-complex type
* 3/6/94 JC
* - C revised in bug search
* 9/6/94 JC
* - im_prepare() was preparing too small an area! oops
* 22/5/95 JC
* - added code to detect all-black output area case - helps lazy ip
* 3/7/95 JC
* - IM_CODING_LABQ handling moved to here
* 31/7/97 JC
* - dx/dy sign reversed to be less confusing ... now follows comment at
* top ... ax - by + dx etc.
* - tiny speed up, replaced the *++ on interpolation with [z]
* - im_similarity() moved in here
* - args swapped: was whxy, now xywh
* - didn't agree with dispatch fns before :(
* 3/3/98 JC
* - im_demand_hint() added
* 20/12/99 JC
* - im_affine() made from im_similarity_area()
* - transform stuff cleaned up a bit
* 14/4/01 JC
* - oops, invert_point() had a rounding problem
* 23/2/02 JC
* - pre-calculate interpolation matricies
* - integer interpolation for int8/16 types, double for
* int32/float/double
* - faster transformation
* 15/8/02 JC
* - records Xoffset/Yoffset
* 14/4/04
* - rounding, clipping and transforming revised, now pixel-perfect (or
* better than gimp, anyway)
* 22/6/05
* - all revised again, simpler and more reliable now
* 30/3/06
* - gah, still an occasional clipping problem
* 12/7/06
* - still more tweaking, gah again
* 7/10/06
* - set THINSTRIP for no-rotate affines
* 20/10/08
* - version with interpolate parameter, from im_affine()
*/
/*
This file is part of VIPS.
VIPS 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
*/
/*
#define DEBUG
#define DEBUG_GEOMETRY
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <vips/intl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <limits.h>
#include <vips/vips.h>
#include <vips/internal.h>
#include "merge.h"
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
/* "fast" floor() ... on my laptop, anyway.
*/
#define FLOOR( V ) ((V) >= 0 ? (int)(V) : (int)((V) - 1))
/* Map a point through the inverse transform. Used for clipping calculations,
* so it takes account of iarea and oarea.
*/
static void
invert_point( Transformation *trn,
double x, double y, /* In output space */
double *ox, double *oy ) /* In input space */
{
double xin = x - trn->oarea.left - trn->dx;
double yin = y - trn->oarea.top - trn->dy;
/* Find the inverse transform of current (x, y)
*/
*ox = trn->ia * xin + trn->ib * yin;
*oy = trn->ic * xin + trn->id * yin;
}
/* Given a bounding box for an area in the output image, set the bounding box
* for the corresponding pixels in the input image.
*/
static void
invert_rect( Transformation *trn,
Rect *in, /* In output space */
Rect *out ) /* In input space */
{
double x1, y1; /* Map corners */
double x2, y2;
double x3, y3;
double x4, y4;
double left, right, top, bottom;
/* Map input Rect.
*/
invert_point( trn, in->left, in->top, &x1, &y1 );
invert_point( trn, in->left, IM_RECT_BOTTOM(in), &x2, &y2 );
invert_point( trn, IM_RECT_RIGHT(in), in->top, &x3, &y3 );
invert_point( trn, IM_RECT_RIGHT(in), IM_RECT_BOTTOM(in), &x4, &y4 );
/* Find bounding box for these four corners.
*/
left = IM_MIN( x1, IM_MIN( x2, IM_MIN( x3, x4 ) ) );
right = IM_MAX( x1, IM_MAX( x2, IM_MAX( x3, x4 ) ) );
top = IM_MIN( y1, IM_MIN( y2, IM_MIN( y3, y4 ) ) );
bottom = IM_MAX( y1, IM_MAX( y2, IM_MAX( y3, y4 ) ) );
/* Set output Rect.
*/
out->left = left;
out->top = top;
out->width = right - left + 1;
out->height = bottom - top + 1;
}
/* Per-call state.
*/
typedef struct _Affine {
IMAGE *in;
IMAGE *out;
VipsInterpolate *interpolate;
Transformation trn;
} Affine;
static int
affine_free( Affine *affine )
{
IM_FREEF( g_object_unref, affine->interpolate );
return( 0 );
}
static int
affinei_gen( REGION *or, void *seq, void *a, void *b )
{
REGION *ir = (REGION *) seq;
IMAGE *in = (IMAGE *) a;
Affine *affine = (Affine *) b;
const int window_size =
vips_interpolate_get_window_size( affine->interpolate );
const int half_window_size = window_size / 2;
/* Output area for this call.
*/
Rect *r = &or->valid;
int le = r->left;
int ri = IM_RECT_RIGHT(r);
int to = r->top;
int bo = IM_RECT_BOTTOM(r);
Rect *iarea = &affine->trn.iarea;
Rect *oarea = &affine->trn.oarea;
int ps = IM_IMAGE_SIZEOF_PEL( in );
int x, y, z;
/* Clipping Rects.
*/
Rect image, need, clipped;
/* Find the area of the input image we need.
*/
image.left = 0;
image.top = 0;
image.width = in->Xsize;
image.height = in->Ysize;
invert_rect( &affine->trn, r, &need );
/* Add a border for interpolation. You'd think +1 would do it, but
* we need to allow for rounding clipping as well.
*/
im_rect_marginadjust( &need, window_size );
im_rect_intersectrect( &need, &image, &clipped );
/* Outside input image? All black.
*/
if( im_rect_isempty( &clipped ) ) {
im__black_region( or );
return( 0 );
}
/* We do need some pixels from the input image to make our output -
* ask for them.
*/
if( im_prepare( ir, &clipped ) )
return( -1 );
#ifdef DEBUG
printf( "affine: preparing left=%d, top=%d, width=%d, height=%d\n",
clipped.left,
clipped.top,
clipped.width,
clipped.height );
#endif /*DEBUG*/
/* Resample!
*/
for( y = to; y < bo; y++ ) {
/* Continuous cods in output space.
*/
double oy = y - oarea->top - affine->trn.dy;
double ox;
/* Input clipping rectangle.
*/
int ile = iarea->left;
int ito = iarea->top;
int iri = iarea->left + iarea->width;
int ibo = iarea->top + iarea->height;
/* Derivative of matrix.
*/
double dx = affine->trn.ia;
double dy = affine->trn.ic;
/* Continuous cods in input space.
*/
double ix, iy;
PEL *q;
ox = le - oarea->left - affine->trn.dx;
ix = affine->trn.ia * ox + affine->trn.ib * oy;
iy = affine->trn.ic * ox + affine->trn.id * oy;
/* Offset ix/iy input by iarea.left/top ... so we skip the
* image edges we added for interpolation.
*/
ix += iarea->left;
iy += iarea->top;
q = (PEL *) IM_REGION_ADDR( or, le, y );
for( x = le; x < ri; x++ ) {
int fx, fy;
fx = FLOOR( ix );
fy = FLOOR( iy );
/* Clipping! Use >= for right/bottom, since IPOL needs
* to see one pixel more each way.
*/
if( fx <= ile - half_window_size ||
fx >= iri + half_window_size ||
fy <= ito - half_window_size ||
fy >= ibo + half_window_size ) {
for( z = 0; z < ps; z++ )
q[z] = 0;
}
else {
vips_interpolate( affine->interpolate, or, ir,
x, y, ix, iy );
}
ix += dx;
iy += dy;
q += ps;
}
}
return( 0 );
}
static int
affinei( IMAGE *in, IMAGE *out,
VipsInterpolate *interpolate, Transformation *trn )
{
Affine *affine;
double edge;
if( im_iscomplex( in ) ) {
im_error( "im_affinei", _( "complex input not supported" ) );
return( -1 );
}
/* Make output image.
*/
if( im_piocheck( in, out ) )
return( -1 );
if( im_cp_desc( out, in ) )
return( -1 );
/* Need a copy of the params for the lifetime of out.
*/
if( !(affine = IM_NEW( out, Affine )) )
return( -1 );
affine->interpolate = NULL;
if( im_add_close_callback( out,
(im_callback_fn) affine_free, affine, NULL ) )
return( -1 );
affine->in = in;
affine->out = out;
affine->interpolate = interpolate;
g_object_ref( interpolate );
affine->trn = *trn;
/* We output at (0,0), so displace output by that amount -ve to get
* output at (ox,oy). Alter our copy of trn.
*/
affine->trn.oarea.left = -affine->trn.oarea.left;
affine->trn.oarea.top = -affine->trn.oarea.top;
if( im__transform_calc_inverse( &affine->trn ) )
return( -1 );
out->Xsize = affine->trn.oarea.width;
out->Ysize = affine->trn.oarea.height;
/* Normally SMALLTILE ... except if this is a size up/down affine.
*/
if( affine->trn.b == 0.0 && affine->trn.c == 0.0 ) {
if( im_demand_hint( out, IM_FATSTRIP, in, NULL ) )
return( -1 );
}
else {
if( im_demand_hint( out, IM_SMALLTILE, in, NULL ) )
return( -1 );
}
/* Check for coordinate overflow ... we want to be able to hold the
* output space inside INT_MAX / TRANSFORM_SCALE.
*/
edge = INT_MAX / VIPS_TRANSFORM_SCALE;
if( affine->trn.oarea.left < -edge || affine->trn.oarea.top < -edge ||
IM_RECT_RIGHT( &affine->trn.oarea ) > edge ||
IM_RECT_BOTTOM( &affine->trn.oarea ) > edge ) {
im_error( "im_affinei",
_( "output coordinates out of range" ) );
return( -1 );
}
/* Generate!
*/
if( im_generate( out,
im_start_one, affinei_gen, im_stop_one, in, affine ) )
return( -1 );
return( 0 );
}
/* As above, but do IM_CODING_LABQ too. And embed the input.
*/
int
im__affinei( IMAGE *in, IMAGE *out,
VipsInterpolate *interpolate, Transformation *trn )
{
IMAGE *t3 = im_open_local( out, "im_affine:3", "p" );
const int window_size = vips_interpolate_get_window_size( interpolate );
Transformation trn2;
#ifdef DEBUG_GEOMETRY
printf( "im__affinei: %s\n", in->filename );
im__transform_print( trn );
#endif /*DEBUG_GEOMETRY*/
/* Add new pixels around the input so we can interpolate at the edges.
*/
if( !t3 ||
im_embed( in, t3, 1,
window_size / 2, window_size / 2,
in->Xsize + window_size, in->Ysize + window_size ) )
return( -1 );
/* Set iarea so we know what part of the input we can take.
*/
trn2 = *trn;
trn2.iarea.left += window_size / 2;
trn2.iarea.top += window_size / 2;
if( in->Coding == IM_CODING_LABQ ) {
IMAGE *t1 = im_open_local( out, "im_affine:1", "p" );
IMAGE *t2 = im_open_local( out, "im_affine:2", "p" );
if( !t1 || !t2 ||
im_LabQ2LabS( t3, t1 ) ||
affinei( t1, t2, interpolate, &trn2 ) ||
im_LabS2LabQ( t2, out ) )
return( -1 );
}
else if( in->Coding == IM_CODING_NONE ) {
if( affinei( t3, out, interpolate, &trn2 ) )
return( -1 );
}
else {
im_error( "im_affinei", _( "unknown coding type" ) );
return( -1 );
}
/* Finally: can now set Xoffset/Yoffset.
*/
out->Xoffset = trn->dx - trn->oarea.left;
out->Yoffset = trn->dy - trn->oarea.top;
return( 0 );
}
int
im_affinei( IMAGE *in, IMAGE *out, VipsInterpolate *interpolate,
double a, double b, double c, double d,
double dx, double dy,
int ox, int oy, int ow, int oh )
{
Transformation trn;
trn.iarea.left = 0;
trn.iarea.top = 0;
trn.iarea.width = in->Xsize;
trn.iarea.height = in->Ysize;
trn.oarea.left = ox;
trn.oarea.top = oy;
trn.oarea.width = ow;
trn.oarea.height = oh;
trn.a = a;
trn.b = b;
trn.c = c;
trn.d = d;
trn.dx = dx;
trn.dy = dy;
return( im__affinei( in, out, interpolate, &trn ) );
}
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