libvips/libvips/morphology/morphology.c

151 lines
4.6 KiB
C

/* base class for all morphological operations
*
* properties:
* - one input image
*/
/*
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 "pmorphology.h"
/**
* SECTION: morphology
* @short_description: morphological operators, rank filters and related image
* analysis
* @see_also: <link linkend="libvips-arithmetic">arithmetic</link>
* @stability: Stable
* @include: vips/vips.h
*
* The morphological functions search images
* for particular patterns of pixels, specified with the mask argument,
* either adding or removing pixels when they find a match. They are useful
* for cleaning up images --- for example, you might threshold an image, and
* then use one of the morphological functions to remove all single isolated
* pixels from the result.
*
* If you combine the morphological operators with the mask rotators
* (vips_rot45(), for example) and apply them repeatedly, you
* can achieve very complicated effects: you can thin, prune, fill, open edges,
* close gaps, and many others. For example, see `Fundamentals of Digital
* Image Processing' by A. Jain, pp 384-388, Prentice-Hall, 1989 for more
* ideas.
*
* Beware that VIPS reverses the usual image processing convention, by
* assuming white objects (non-zero pixels) on a black background (zero
* pixels).
*
* The mask you give to the morphological functions should contain only the
* values 0 (for background), 128 (for don't care) and 255 (for object). The
* mask must have odd length sides --- the origin of the mask is taken to be
* the centre value. For example, the mask:
*
* VipsImage *mask = vips_image_new_matrixv( 3, 3,
* 128.0, 255.0, 128.0,
* 255.0, 255.0, 255.0,
* 128.0, 255.0, 128.0 );
*
* applied to an image with vips_morph() #VIPS_OPERATION_MORPHOLOGY_DILATE will
* do a 4-connected dilation.
*
* Dilate sets pixels in the output if any part of the mask matches, whereas
* erode sets pixels only if all of the mask matches.
*
* See vips_andimage(), vips_orimage() and vips_eorimage()
* for analogues of the usual set difference and set union operations.
*
* Use vips_image_new_matrixv() to create a mask in source, vips_matrixload()
* to load a mask from a simple text file, and vips_mask_ideal() and friends to
* create square, circular and ring masks of specific sizes.
*/
G_DEFINE_ABSTRACT_TYPE( VipsMorphology, vips_morphology,
VIPS_TYPE_OPERATION );
static void
vips_morphology_class_init( VipsMorphologyClass *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 = "morphology";
vobject_class->description = _( "morphological operations" );
/* Inputs set by subclassess.
*/
VIPS_ARG_IMAGE( class, "in", 0,
_( "Input" ),
_( "Input image argument" ),
VIPS_ARGUMENT_REQUIRED_INPUT,
G_STRUCT_OFFSET( VipsMorphology, in ) );
}
static void
vips_morphology_init( VipsMorphology *morphology )
{
}
/* Called from iofuncs to init all operations in this dir. Use a plugin system
* instead?
*/
void
vips_morphology_operation_init( void )
{
extern GType vips_morph_get_type( void );
extern GType vips_rank_get_type( void );
extern GType vips_countlines_get_type( void );
extern GType vips_labelregions_get_type( void );
extern GType vips_fill_nearest_get_type( void );
vips_morph_get_type();
vips_rank_get_type();
vips_countlines_get_type();
vips_labelregions_get_type();
vips_fill_nearest_get_type();
}