libvips/libsrc/histograms_lut/im_project.c

/* @(#) Find the horizontal and vertical projections of an image, ie. the sum
 * @(#) of pixels in each row and column. Two output images, 1xheight and
 * @(#) widthx1, with the largest required bandfmt. 
 * @(#) 
 * @(#) int im_project( in, columns, rows )
 * @(#) IMAGE *in;
 * @(#) IMAGE *columns, *rows;
 * @(#)
 * @(#) Returns 0 on success and -1 on error
 *
 * 20/4/06
 *	- from im_histgr()
 */

/*

    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

 */

#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 <assert.h>

#include <vips/vips.h>

#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/

/* Accumulate a projection in one of these.
 */
typedef struct {
	IMAGE *in;
	IMAGE *hout;
	IMAGE *vout;
	void *columns;
	void *rows;
} Project;

/* For each input bandfmt, the type we accumulate pixels in.
 */
static int project_type[] = {
	IM_BANDFMT_UINT,	/* IM_BANDFMT_UCHAR */
	IM_BANDFMT_INT,		/* IM_BANDFMT_CHAR */
	IM_BANDFMT_UINT,	/* IM_BANDFMT_USHORT */
	IM_BANDFMT_INT,		/* IM_BANDFMT_SHORT */
	IM_BANDFMT_UINT,	/* IM_BANDFMT_UINT */
	IM_BANDFMT_INT,		/* IM_BANDFMT_INT */
	IM_BANDFMT_DOUBLE,	/* IM_BANDFMT_FLOAT */
	IM_BANDFMT_NOTSET,	/* IM_BANDFMT_COMPLEX */
	IM_BANDFMT_DOUBLE,	/* IM_BANDFMT_DOUBLE */
	IM_BANDFMT_NOTSET	/* IM_BANDFMT_DPCOMPLEX */
};

static Project *
project_new( IMAGE *in, IMAGE *hout, IMAGE *vout )
{
	Project *project;
	int psize = IM_IMAGE_SIZEOF_PEL( hout );

	if( !(project = IM_NEW( hout, Project )) )
		return( NULL );
	project->in = in;
	project->hout = hout;
	project->vout = vout;
	project->columns = IM_ARRAY( hout, psize * in->Xsize, guchar );
	project->rows = IM_ARRAY( hout, psize * in->Ysize, guchar );
	if( !project->columns || !project->rows )
		return( NULL );

	memset( project->columns, 0, psize * in->Xsize );
	memset( project->rows, 0, psize * in->Ysize );

	return( project );
}

/* Build a sub-project, based on the main project.
 */
static void *
project_new_sub( IMAGE *out, Project *mproject )
{
	return( (void *) 
		project_new( mproject->in, mproject->hout, mproject->vout ) );
}

#define ADD_BUFFER( TYPE, Q, P, N ) { \
	TYPE *p = (TYPE *) (P); \
	TYPE *q = (TYPE *) (Q); \
	int n = (N); \
	int i; \
	\
	for( i = 0; i < n; i++ ) \
		q[i] += p[i]; \
}

/* Join a sub-project onto the main project.
 */
static int
project_merge( Project *sproject, Project *mproject )
{
	IMAGE *in = mproject->in;
	IMAGE *out = mproject->hout;
	int hsz = in->Xsize * in->Bands;
	int vsz = in->Ysize * in->Bands;

	assert( sproject->hout == mproject->hout );
	assert( sproject->vout == mproject->vout );

	/* Add on sub-data.
	 */
	switch( out->BandFmt ) {
	case IM_BANDFMT_UINT:
		ADD_BUFFER( guint, mproject->columns, sproject->columns, hsz );
		ADD_BUFFER( guint, mproject->rows, sproject->rows, vsz );
		break;

	case IM_BANDFMT_INT:
		ADD_BUFFER( int, mproject->columns, sproject->columns, hsz );
		ADD_BUFFER( int, mproject->rows, sproject->rows, vsz );
		break;

	case IM_BANDFMT_DOUBLE:
		ADD_BUFFER( double, mproject->columns, sproject->columns, hsz );
		ADD_BUFFER( double, mproject->rows, sproject->rows, vsz );
		break;

	default:
		assert( 0 );
	}

	/* Blank out sub-project to make sure we can't add it again.
	 */
	memset( sproject->columns, 0, IM_IMAGE_SIZEOF_ELEMENT( out ) * hsz );
	memset( sproject->rows, 0, IM_IMAGE_SIZEOF_ELEMENT( out ) * vsz );

	return( 0 );
}

/* Add an area of pixels.
 */
#define ADD_PIXELS( OUTTYPE, INTYPE ) { \
	OUTTYPE *rows; \
	OUTTYPE *columns; \
	INTYPE *p; \
	\
	rows = ((OUTTYPE *) project->rows) + to * nb; \
	for( y = 0; y < r->height; y++ ) { \
		columns = ((OUTTYPE *) project->columns) + le * nb; \
		p = (INTYPE *) IM_REGION_ADDR( reg, le, y + to ); \
		\
		for( x = 0; x < r->width; x++ ) { \
			for( z = 0; z < nb; z++ ) { \
				columns[z] += p[z]; \
				rows[z] += p[z]; \
			} \
			\
			p += nb; \
			columns += nb; \
		} \
		\
		rows += nb; \
	} \
}

/* Add a region to a project.
 */
static int
project_scan( REGION *reg, Project *project )
{
	Rect *r = &reg->valid;
	int le = r->left;
	int to = r->top;
	int nb = project->in->Bands;
	int x, y, z;

	switch( project->in->BandFmt ) {
	case IM_BANDFMT_UCHAR:
		ADD_PIXELS( guint, guchar );
		break;

	case IM_BANDFMT_CHAR:
		ADD_PIXELS( int, char );
		break;

	case IM_BANDFMT_USHORT:
		ADD_PIXELS( guint, gushort );
		break;

	case IM_BANDFMT_SHORT:
		ADD_PIXELS( int, short );
		break;

	case IM_BANDFMT_UINT:
		ADD_PIXELS( guint, guint );
		break;

	case IM_BANDFMT_INT:
		ADD_PIXELS( int, int );
		break;

	case IM_BANDFMT_FLOAT:
		ADD_PIXELS( double, float );
		break;

	case IM_BANDFMT_DOUBLE:
		ADD_PIXELS( double, double );
		break;

	default:
		assert( 0 );
	}

	return( 0 );
}

int 
im_project( IMAGE *in, IMAGE *hout, IMAGE *vout )
{
	Project *mproject;
	int y;

	/* Check images. PIO from in, WIO to out.
	 */
	if( im_pincheck( in ) || im_outcheck( hout ) || im_outcheck( vout ) )
		return( -1 );
	if( in->Coding != IM_CODING_NONE ) {
		im_error( "im_project", _( "uncoded images only" ) );
		return( -1 );
	}
	if( im_iscomplex( in ) ) {
		im_error( "im_project", _( "non-complex images only" ) );
		return( -1 );
	}

	/* Make the output images. 
	 */
	if( im_cp_desc( hout, in ) || im_cp_desc( vout, in ) ) 
		return( -1 );

	hout->Xsize = 1;
	hout->BandFmt = project_type[in->BandFmt];
	hout->Bbits = im_bits_of_fmt( hout->BandFmt );
	hout->Type = IM_TYPE_HISTOGRAM;

	vout->Ysize = 1;
	vout->BandFmt = project_type[in->BandFmt];
	vout->Bbits = im_bits_of_fmt( hout->BandFmt );
	vout->Type = IM_TYPE_HISTOGRAM;

	/* Build the main project we accumulate data in.
	 */
	if( !(mproject = project_new( in, hout, vout )) )
		return( -1 );

	/* Accumulate data.
	 */
	if( im_iterate( in, 
		project_new_sub, project_scan, project_merge, mproject, NULL ) )
		return( -1 );

	if( im_setupout( hout ) || im_setupout( vout ) )
		return( -1 );

	if( im_writeline( 0, vout, (PEL *) mproject->columns ) )
		return( -1 );
	for( y = 0; y < in->Ysize; y++ )
		if( im_writeline( y, hout, (PEL *) mproject->rows + 
			y * IM_IMAGE_SIZEOF_PEL( hout ) ) )
			return( -1 );

	return( 0 );
}