static int
vips_merge_build( VipsObject *object )
{
VipsMerge *merge = (VipsMerge *) object;
g_object_set( merge, "out", vips_image_new(), NULL );
if( VIPS_OBJECT_CLASS( vips_merge_parent_class )->build( object ) )
return( -1 );
switch( merge->direction ) {
case VIPS_DIRECTION_HORIZONTAL:
if( im_lrmerge( merge->ref, merge->sec, merge->out,
merge->dx, merge->dy, merge->mblend ) )
return( -1 );
break;
case VIPS_DIRECTION_VERTICAL:
if( im_tbmerge( merge->ref, merge->sec, merge->out,
merge->dx, merge->dy, merge->mblend ) )
return( -1 );
break;
default:
g_assert( 0 );
}
return( 0 );
}
/**
* im_tbmosaic:
* @ref: reference image
* @sec: secondary image
* @out: output image
* @bandno: band to search for features
* @xref: position in reference image
* @yref: position in reference image
* @xsec: position in secondary image
* @ysec: position in secondary image
* @hwindowsize: half window size
* @hsearchsize: half search size
* @balancetype: no longer used
* @mwidth: maximum blend width
*
* This operation joins two images top-bottom (with @ref on the top)
* given an approximate overlap.
*
* @sec is positioned so that the pixel (@xsec, @ysec) lies on top of the
* pixel in @ref at (@xref, @yref). The overlap area is divided into three
* sections, 20 high-contrast points in band @bandno of image @ref are found
* in each, and each high-contrast point is searched for in @sec using
* @hwindowsize and @hsearchsize (see im_correl()).
*
* A linear model is fitted to the 60 tie-points, points a long way from the
* fit are discarded, and the model refitted until either too few points
* remain or the model reaches good agreement.
*
* The detected displacement is used with im_tbmerge() to join the two images
* together.
*
* @mwidth limits the maximum height of the
* blend area. A value of "-1" means "unlimited". The two images are blended
* with a raised cosine.
*
* Pixels with all bands equal to zero are "transparent", that
* is, zero pixels in the overlap area do not contribute to the merge.
* This makes it possible to join non-rectangular images.
*
* If the number of bands differs, one of the images
* must have one band. In this case, an n-band image is formed from the
* one-band image by joining n copies of the one-band image together, and then
* the two n-band images are operated upon.
*
* The two input images are cast up to the smallest common type (see table
* Smallest common format in
* <link linkend="VIPS-arithmetic">arithmetic</link>).
*
* See also: im_tbmerge(), im_lrmosaic(), im_insert(), im_global_balance().
*
* Returns: 0 on success, -1 on error
*/
int
im_tbmosaic( IMAGE *ref, IMAGE *sec, IMAGE *out,
int bandno,
int xref, int yref, int xsec, int ysec,
int hwindowsize, int hsearchsize,
int balancetype,
int mwidth )
{
int dx0, dy0;
double scale1, angle1, dx1, dy1;
IMAGE *dummy;
/* Correct overlap. dummy is just a placeholder used to ensure that
* memory used by the analysis phase is freed as soon as possible.
*/
if( !(dummy = im_open( "placeholder:1", "p" )) )
return( -1 );
if( im__find_tboverlap( ref, sec, dummy,
bandno,
xref, yref, xsec, ysec,
hwindowsize, hsearchsize,
&dx0, &dy0,
&scale1, &angle1, &dx1, &dy1 ) ) {
im_close( dummy );
return( -1 );
}
im_close( dummy );
/* Merge top-bottom.
*/
if( im_tbmerge( ref, sec, out, dx0, dy0, mwidth ) )
return( -1 );
return( 0 );
}
/* Call im_tbmerge via arg vector.
*/
static int
tbmerge_vec( im_object *argv )
{
int dx = *((int *) argv[3]);
int dy = *((int *) argv[4]);
int mwidth = *((int *) argv[5]);
return( im_tbmerge( argv[0], argv[1], argv[2], dx, dy, mwidth ) );
}
