www.pudn.com > OpenCV-Intel.zip > cvdominants.cpp
/*M///////////////////////////////////////////////////////////////////////////////////////
//
// IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
//
// By downloading, copying, installing or using the software you agree to this license.
// If you do not agree to this license, do not download, install,
// copy or use the software.
//
//
// Intel License Agreement
// For Open Source Computer Vision Library
//
// Copyright (C) 2000, Intel Corporation, all rights reserved.
// Third party copyrights are property of their respective owners.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
// * Redistribution's of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// * Redistribution's in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// * The name of Intel Corporation may not be used to endorse or promote products
// derived from this software without specific prior written permission.
//
// This software is provided by the copyright holders and contributors "as is" and
// any express or implied warranties, including, but not limited to, the implied
// warranties of merchantability and fitness for a particular purpose are disclaimed.
// In no event shall the Intel Corporation or contributors be liable for any direct,
// indirect, incidental, special, exemplary, or consequential damages
// (including, but not limited to, procurement of substitute goods or services;
// loss of use, data, or profits; or business interruption) however caused
// and on any theory of liability, whether in contract, strict liability,
// or tort (including negligence or otherwise) arising in any way out of
// the use of this software, even if advised of the possibility of such damage.
//
//M*/
#include "_cv.h"
typedef struct _PointInfo
{
CvPoint pt;
int left_neigh;
int right_neigh;
}
icvPointInfo;
static CvStatus
icvFindDominantPointsIPAN( CvSeq * contour,
CvMemStorage * storage,
CvSeq ** corners, int dmin2, int dmax2, int dneigh2, float amax )
{
CvStatus status = CV_OK;
/* variables */
int n = contour->total;
float *sharpness;
float *distance;
icvPointInfo *ptInf;
int i, j, k;
CvSeqWriter writer;
float mincos = (float) cos( 3.14159265359 * amax / 180 );
/* check bad arguments */
if( contour == NULL )
return CV_NULLPTR_ERR;
if( storage == NULL )
return CV_NULLPTR_ERR;
if( corners == NULL )
return CV_NULLPTR_ERR;
if( dmin2 < 0 )
return CV_BADSIZE_ERR;
if( dmax2 < dmin2 )
return CV_BADSIZE_ERR;
if( (dneigh2 > dmax2) || (dneigh2 < 0) )
return CV_BADSIZE_ERR;
if( (amax < 0) || (amax > 180) )
return CV_BADSIZE_ERR;
sharpness = (float *) cvAlloc( n * sizeof( float ));
distance = (float *) cvAlloc( n * sizeof( float ));
ptInf = (icvPointInfo *) cvAlloc( n * sizeof( icvPointInfo ));
/*****************************************************************************************/
/* First pass */
/*****************************************************************************************/
if( CV_IS_SEQ_CHAIN_CONTOUR( contour ))
{
CvChainPtReader reader;
cvStartReadChainPoints( (CvChain *) contour, &reader );
for( i = 0; i < n; i++ )
{
CV_READ_CHAIN_POINT( ptInf[i].pt, reader );
}
}
else if( CV_IS_SEQ_POLYGON( contour ))
{
CvSeqReader reader;
cvStartReadSeq( contour, &reader, 0 );
for( i = 0; i < n; i++ )
{
CV_READ_SEQ_ELEM( ptInf[i].pt, reader );
}
}
else
{
return CV_BADFLAG_ERR;
}
for( i = 0; i < n; i++ )
{
/* find nearest suitable points
which satisfy distance constraint >dmin */
int left_near = 0;
int right_near = 0;
int left_far, right_far;
float dist_l = 0;
float dist_r = 0;
int i_plus = 0;
int i_minus = 0;
float max_cos_alpha;
/* find right minimum */
while( dist_r < dmin2 )
{
float dx, dy;
int ind;
if( i_plus >= n )
goto error;
right_near = i_plus;
if( dist_r < dneigh2 )
ptInf[i].right_neigh = i_plus;
i_plus++;
ind = (i + i_plus) % n;
dx = (float) (ptInf[i].pt.x - ptInf[ind].pt.x);
dy = (float) (ptInf[i].pt.y - ptInf[ind].pt.y);
dist_r = dx * dx + dy * dy;
}
/* find right maximum */
while( dist_r <= dmax2 )
{
float dx, dy;
int ind;
if( i_plus >= n )
goto error;
distance[(i + i_plus) % n] = cvSqrt( dist_r );
if( dist_r < dneigh2 )
ptInf[i].right_neigh = i_plus;
i_plus++;
right_far = i_plus;
ind = (i + i_plus) % n;
dx = (float) (ptInf[i].pt.x - ptInf[ind].pt.x);
dy = (float) (ptInf[i].pt.y - ptInf[ind].pt.y);
dist_r = dx * dx + dy * dy;
}
right_far = i_plus;
/* left minimum */
while( dist_l < dmin2 )
{
float dx, dy;
int ind;
if( i_minus <= -n )
goto error;
left_near = i_minus;
if( dist_l < dneigh2 )
ptInf[i].left_neigh = i_minus;
i_minus--;
ind = i + i_minus;
ind = (ind < 0) ? (n + ind) : ind;
dx = (float) (ptInf[i].pt.x - ptInf[ind].pt.x);
dy = (float) (ptInf[i].pt.y - ptInf[ind].pt.y);
dist_l = dx * dx + dy * dy;
}
/* find left maximum */
while( dist_l <= dmax2 )
{
float dx, dy;
int ind;
if( i_minus <= -n )
goto error;
ind = i + i_minus;
ind = (ind < 0) ? (n + ind) : ind;
distance[ind] = cvSqrt( dist_l );
if( dist_l < dneigh2 )
ptInf[i].left_neigh = i_minus;
i_minus--;
left_far = i_minus;
ind = i + i_minus;
ind = (ind < 0) ? (n + ind) : ind;
dx = (float) (ptInf[i].pt.x - ptInf[ind].pt.x);
dy = (float) (ptInf[i].pt.y - ptInf[ind].pt.y);
dist_l = dx * dx + dy * dy;
}
left_far = i_minus;
if( (i_plus - i_minus) > n + 2 )
goto error;
max_cos_alpha = -1;
for( j = left_far + 1; j < left_near; j++ )
{
float dx, dy;
float a, a2;
int leftind = i + j;
leftind = (leftind < 0) ? (n + leftind) : leftind;
a = distance[leftind];
a2 = a * a;
for( k = right_near + 1; k < right_far; k++ )
{
int ind = (i + k) % n;
float c2, cosalpha;
float b = distance[ind];
float b2 = b * b;
/* compute cosinus */
dx = (float) (ptInf[leftind].pt.x - ptInf[ind].pt.x);
dy = (float) (ptInf[leftind].pt.y - ptInf[ind].pt.y);
c2 = dx * dx + dy * dy;
cosalpha = (a2 + b2 - c2) / (2 * a * b);
max_cos_alpha = MAX( max_cos_alpha, cosalpha );
if( max_cos_alpha < mincos )
max_cos_alpha = -1;
sharpness[i] = max_cos_alpha;
}
}
}
/*****************************************************************************************/
/* Second pass */
/*****************************************************************************************/
cvStartWriteSeq( (contour->flags & ~CV_SEQ_ELTYPE_MASK) | CV_SEQ_ELTYPE_INDEX,
sizeof( CvSeq ), sizeof( int ), storage, &writer );
/* second pass - nonmaxima suppression */
/* neighborhood of point < dneigh2 */
for( i = 0; i < n; i++ )
{
int suppressed = 0;
if( sharpness[i] == -1 )
continue;
for( j = 1; (j <= ptInf[i].right_neigh) && (suppressed == 0); j++ )
{
if( sharpness[i] < sharpness[(i + j) % n] )
suppressed = 1;
}
for( j = -1; (j >= ptInf[i].left_neigh) && (suppressed == 0); j-- )
{
int ind = i + j;
ind = (ind < 0) ? (n + ind) : ind;
if( sharpness[i] < sharpness[ind] )
suppressed = 1;
}
if( !suppressed )
CV_WRITE_SEQ_ELEM( i, writer );
}
*corners = cvEndWriteSeq( &writer );
cvFree( (void**)&sharpness );
cvFree( (void**)&distance );
cvFree( (void**)&ptInf );
return status;
error:
/* dmax is so big (more than contour diameter)
that algorithm could become infinite cycle */
cvFree( (void**)&sharpness );
cvFree( (void**)&distance );
cvFree( (void**)&ptInf );
return CV_BADRANGE_ERR;
}
/*F///////////////////////////////////////////////////////////////////////////////////////
// Name: icvFindDominantPoints
// Purpose:
// Applies some algorithm to find dominant points ( corners ) of contour
//
// Context:
// Parameters:
// contours - pointer to input contour object.
// out_numbers - array of dominant points indices
// count - length of out_numbers array on input
// and numbers of founded dominant points on output
//
// method - only CV_DOMINANT_IPAN now
// parameters - array of parameters
// for IPAN algorithm
// [0] - minimal distance
// [1] - maximal distance
// [2] - neighborhood distance (must be not greater than dmaximal distance)
// [3] - maximal possible angle of curvature
// Returns:
// CV_OK or error code
// Notes:
// User must allocate out_numbers array. If it is small - function fills array
// with part of points and returns error
//F*/
CV_IMPL CvSeq*
cvFindDominantPoints( CvSeq * contour, CvMemStorage * storage, int method,
double parameter1, double parameter2, double parameter3, double parameter4 )
{
CvSeq* corners = 0;
CV_FUNCNAME( "cvFindDominantPoints" );
__BEGIN__;
if( !contour )
CV_ERROR( CV_StsNullPtr, "" );
if( !storage )
storage = contour->storage;
if( !storage )
CV_ERROR( CV_StsNullPtr, "" );
switch (method)
{
case CV_DOMINANT_IPAN:
{
int dmin = cvRound(parameter1);
int dmax = cvRound(parameter2);
int dneigh = cvRound(parameter3);
int amax = cvRound(parameter4);
if( amax == 0 )
amax = 150;
if( dmin == 0 )
dmin = 7;
if( dmax == 0 )
dmax = dmin + 2;
if( dneigh == 0 )
dneigh = dmin;
IPPI_CALL( icvFindDominantPointsIPAN( contour, storage, &corners,
dmin*dmin, dmax*dmax, dneigh*dneigh, (float)amax ));
}
break;
default:
CV_ERROR_FROM_STATUS( CV_BADFLAG_ERR );
}
__END__;
return corners;
}
/* End of file. */