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/* base class for all resample operations
*
* properties:
* - one in, one out
* - not point-to-point
* - size can change in any way
* - bands, type, format etc. all fixed
*/
/*
Copyright (C) 1991-2005 The National Gallery
This library 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 2.1 of the License, or (at your option) any later version.
This library 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 library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
/*
#define DEBUG
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <glib/gi18n-lib.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <vips/vips.h>
#include <vips/internal.h>
#include "presample.h"
/**
* SECTION: resample
* @short_description: resample images in various ways
* @stability: Stable
* @include: vips/vips.h
*
* These operations build on each other in a set of layers.
*
* First, vips_affine() applies an affine transform to an image. This is any
* sort of 2D transform which preserves straight lines; so any combination of
* stretch, sheer, rotate and translate. You supply an interpolator for it to
* use to generate pixels, see vips_interpolate_new(). It will not produce
* good results for very large shrinks: you'll see aliasing.
*
* vips_reduce() is like vips_affine(), but it can only shrink images, it can't
* enlarge, rotate, or skew. It's very fast and uses an adaptive kernel for
* interpolation.
*
* vips_shrink() is a fast block shrinker. It can quickly reduce images by
* large integer factors. It will give poor results for small size reductions:
* again, you'll see aliasing.
*
* Next, vips_resize() specialises in the common task of image reduce and
* enlarge. It strings together combinations of vips_shrink(), vips_reduce(),
* vips_affine() and others to implement a general, high-quality image
* resizer.
*
* Finally, vips_thumbnail() combines load and resize in one operation, and adds
* colour management and correct handling of alpha transparency. Because load
* and resize happen together, it can exploit tricks like JPEG and TIFF
* shrink-on-load, giving a (potentially) huge speedup. vips_thumbnail_image()
* is only there for emergencies, don't use it unless you really have to.
*
* As a separate thing, `vips_mapim() can apply arbitrary 2D image transforms
* to an image.
*/
/**
* VipsSize:
* @VIPS_SIZE_BOTH: size both up and down
* @VIPS_SIZE_UP: only upsize
* @VIPS_SIZE_DOWN: only downsize
* @VIPS_SIZE_FORCE: force size, that is, break aspect ratio
*
* Controls whether an operation should upsize, downsize, both up and
* downsize, or force a size.
*
* See also: vips_thumbnail().
*/
G_DEFINE_ABSTRACT_TYPE( VipsResample, vips_resample, VIPS_TYPE_OPERATION );
static int
vips_resample_build( VipsObject *object )
{
VipsResample *resample = VIPS_RESAMPLE( object );
#ifdef DEBUG
printf( "vips_resample_build: " );
vips_object_print_name( object );
printf( "\n" );
#endif /*DEBUG*/
g_object_set( resample, "out", vips_image_new(), NULL );
if( VIPS_OBJECT_CLASS( vips_resample_parent_class )->build( object ) )
return( -1 );
return( 0 );
}
static void
vips_resample_class_init( VipsResampleClass *class )
{
GObjectClass *gobject_class = G_OBJECT_CLASS( class );
VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
gobject_class->set_property = vips_object_set_property;
gobject_class->get_property = vips_object_get_property;
vobject_class->nickname = "resample";
vobject_class->description = _( "resample operations" );
vobject_class->build = vips_resample_build;
VIPS_ARG_IMAGE( class, "in", 1,
_( "Input" ),
_( "Input image argument" ),
VIPS_ARGUMENT_REQUIRED_INPUT,
G_STRUCT_OFFSET( VipsResample, in ) );
VIPS_ARG_IMAGE( class, "out", 2,
_( "Output" ),
_( "Output image" ),
VIPS_ARGUMENT_REQUIRED_OUTPUT,
G_STRUCT_OFFSET( VipsResample, out ) );
}
static void
vips_resample_init( VipsResample *resample )
{
}
/* Called from iofuncs to init all operations in this dir. Use a plugin system
* instead?
*/
void
vips_resample_operation_init( void )
{
extern GType vips_thumbnail_file_get_type( void );
extern GType vips_thumbnail_buffer_get_type( void );
extern GType vips_thumbnail_image_get_type( void );
extern GType vips_thumbnail_source_get_type( void );
extern GType vips_mapim_get_type( void );
extern GType vips_shrink_get_type( void );
extern GType vips_shrinkh_get_type( void );
extern GType vips_shrinkv_get_type( void );
extern GType vips_reduce_get_type( void );
extern GType vips_reduceh_get_type( void );
extern GType vips_reducev_get_type( void );
extern GType vips_quadratic_get_type( void );
extern GType vips_affine_get_type( void );
extern GType vips_similarity_get_type( void );
extern GType vips_rotate_get_type( void );
extern GType vips_resize_get_type( void );
vips_thumbnail_file_get_type();
vips_thumbnail_buffer_get_type();
vips_thumbnail_image_get_type();
vips_thumbnail_source_get_type();
vips_mapim_get_type();
vips_shrink_get_type();
vips_shrinkh_get_type();
vips_shrinkv_get_type();
vips_reduceh_get_type();
vips_reducev_get_type();
vips_reduce_get_type();
vips_quadratic_get_type();
vips_affine_get_type();
vips_similarity_get_type();
vips_rotate_get_type();
vips_resize_get_type();
}
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