124 lines
3.9 KiB
C
124 lines
3.9 KiB
C
/* Various interpolators.
|
|
*
|
|
* J.Cupitt, 15/10/08
|
|
*/
|
|
|
|
/*
|
|
|
|
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
|
|
|
|
*/
|
|
|
|
#ifndef VIPS_INTERPOLATE_H
|
|
#define VIPS_INTERPOLATE_H
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif /*__cplusplus*/
|
|
|
|
#define VIPS_TYPE_INTERPOLATE (vips_interpolate_get_type())
|
|
#define VIPS_INTERPOLATE( obj ) \
|
|
(G_TYPE_CHECK_INSTANCE_CAST( (obj), \
|
|
VIPS_TYPE_INTERPOLATE, VipsInterpolate ))
|
|
#define VIPS_INTERPOLATE_CLASS( klass ) \
|
|
(G_TYPE_CHECK_CLASS_CAST( (klass), \
|
|
VIPS_TYPE_INTERPOLATE, VipsInterpolateClass))
|
|
#define VIPS_IS_INTERPOLATE( obj ) \
|
|
(G_TYPE_CHECK_INSTANCE_TYPE( (obj), VIPS_TYPE_INTERPOLATE ))
|
|
#define VIPS_IS_INTERPOLATE_CLASS( klass ) \
|
|
(G_TYPE_CHECK_CLASS_TYPE( (klass), VIPS_TYPE_INTERPOLATE ))
|
|
#define VIPS_INTERPOLATE_GET_CLASS( obj ) \
|
|
(G_TYPE_INSTANCE_GET_CLASS( (obj), \
|
|
VIPS_TYPE_INTERPOLATE, VipsInterpolateClass ))
|
|
|
|
typedef struct _VipsInterpolate {
|
|
VipsObject parent_object;
|
|
|
|
} VipsInterpolate;
|
|
|
|
/* An interpolation function. This is a class method, but we have a lookup
|
|
* function for it to speed up dispatch. Write to the memory at "out",
|
|
* interpolate the value at position (x, y) in "in".
|
|
*/
|
|
typedef void (*VipsInterpolateMethod)( VipsInterpolate *,
|
|
PEL *out, REGION *in, double x, double y );
|
|
|
|
typedef struct _VipsInterpolateClass {
|
|
VipsObjectClass parent_class;
|
|
|
|
/* Write to pixel out(x,y), interpolating from in(x,y). The caller has
|
|
* to set the regions up.
|
|
*/
|
|
VipsInterpolateMethod interpolate;
|
|
|
|
/* This interpolator needs a window this many pixels across and down.
|
|
*/
|
|
int (*get_window_size)( VipsInterpolate * );
|
|
|
|
/* Or just set this if you want a constant.
|
|
*/
|
|
int window_size;
|
|
} VipsInterpolateClass;
|
|
|
|
GType vips_interpolate_get_type( void );
|
|
void vips_interpolate( VipsInterpolate *interpolate,
|
|
PEL *out, REGION *in, double x, double y );
|
|
VipsInterpolateMethod vips_interpolate_get_method( VipsInterpolate * );
|
|
int vips_interpolate_get_window_size( VipsInterpolate *interpolate );
|
|
|
|
/* How many bits of precision we keep for transformations, ie. how many
|
|
* pre-computed matricies we have.
|
|
*/
|
|
#define VIPS_TRANSFORM_SHIFT (5)
|
|
#define VIPS_TRANSFORM_SCALE (1 << VIPS_TRANSFORM_SHIFT)
|
|
|
|
/* How many bits of precision we keep for interpolation, ie. where the decimal
|
|
* is in the fixed-point tables. For 16-bit pixels, we need 16 bits for the
|
|
* data, 4 bits to add 16 values together, another bit for the sign and some
|
|
* other stuff, so say 24 total. That leaves 8 bits for the fractional part.
|
|
*/
|
|
#define VIPS_INTERPOLATE_SHIFT (8)
|
|
#define VIPS_INTERPOLATE_SCALE (1 << VIPS_INTERPOLATE_SHIFT)
|
|
|
|
/* Convenience: return static interpolators, no need to unref.
|
|
*/
|
|
VipsInterpolate *vips_interpolate_nearest_static( void );
|
|
VipsInterpolate *vips_interpolate_bilinear_static( void );
|
|
VipsInterpolate *vips_interpolate_bicubic_static( void );
|
|
|
|
/* Convenience: make an interpolator from a nickname. g_object_unref() when
|
|
* you're done with it.
|
|
*/
|
|
VipsInterpolate *vips_interpolate_new( const char *nickname );
|
|
|
|
/* Register base vips types, called during startup.
|
|
*/
|
|
void vips__interpolate_init( void );
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif /*__cplusplus*/
|
|
|
|
#endif /*VIPS_INTERPOLATE_H*/
|
|
|