/*F///////////////////////////////////////////////////////////////////////////////////////
// Name: cvConDensUpdateByTime
// Purpose: Performing Time Update routine for ConDensation algorithm
// Context:
// Parameters:
// Kalman - pointer to CvConDensation structure
// Returns:
// Notes:
//
//F*/
CV_IMPL void
cvConDensUpdateByTime( CvConDensation * ConDens )
{
int i, j;
float Sum = 0;
CV_FUNCNAME( "cvConDensUpdateByTime" );
__BEGIN__;
if( !ConDens )
CV_ERROR( CV_StsNullPtr, "" );
/* Sets Temp to Zero */
icvSetZero_32f( ConDens->Temp, ConDens->DP, 1 );
/* Calculating the Mean */
for( i = 0; i < ConDens->SamplesNum; i++ )
{
icvScaleVector_32f( ConDens->flSamples[i], ConDens->State, ConDens->DP,
ConDens->flConfidence[i] );
icvAddVector_32f( ConDens->Temp, ConDens->State, ConDens->Temp, ConDens->DP );
Sum += ConDens->flConfidence[i];
ConDens->flCumulative[i] = Sum;
}
/* Taking the new vector from transformation of mean by dynamics matrix */
icvScaleVector_32f( ConDens->Temp, ConDens->Temp, ConDens->DP, 1.f / Sum );
icvTransformVector_32f( ConDens->DynamMatr, ConDens->Temp, ConDens->State, ConDens->DP,
ConDens->DP );
Sum = Sum / ConDens->SamplesNum;
/* Updating the set of random samples */
//重采样，将新采样出来的粒子保存在flNewSamples中
for( i = 0; i < ConDens->SamplesNum; i++ )
{
j = 0;
while( (ConDens->flCumulative[j] <= (float) i * Sum)&&(j<ConDens->SamplesNum-1))
{
j++;
}
icvCopyVector_32f( ConDens->flSamples[j], ConDens->DP, ConDens->flNewSamples[i] );
}
/* Adding the random-generated vector to every vector in sample set */
for( i = 0; i < ConDens->SamplesNum; i++ )
{ //为每个新粒子产生一个随即量
for( j = 0; j < ConDens->DP; j++ )
{
cvbRand( ConDens->RandS + j, ConDens->RandomSample + j, 1 );
}
//将flNewSamples加一个随即量，保存入flSamples中
icvTransformVector_32f( ConDens->DynamMatr, ConDens->flNewSamples[i],
ConDens->flSamples[i], ConDens->DP, ConDens->DP );
icvAddVector_32f( ConDens->flSamples[i], ConDens->RandomSample, ConDens->flSamples[i],
ConDens->DP );
}
__END__;
}
static CvStatus CV_STDCALL
icvFindHandRegion( CvPoint3D32f * points, int count,
CvSeq * indexs,
float *line, CvSize2D32f size, int flag,
CvPoint3D32f * center,
CvMemStorage * storage, CvSeq ** numbers )
{
/* IppmVect32f sub, cros; */
float *sub, *cros;
CvSeqWriter writer;
CvSeqReader reader;
CvStatus status;
int nbins = 20, i, l, i_point, left, right;
int *bin_counts = 0; // pointer to the point's counter in the bickets
int low_count; // low threshold
CvPoint *tmp_number = 0, *pt;
float value, vmin, vmax, vl, bsize, vc;
float hand_length, hand_length2, hand_left, hand_right;
float threshold, threshold2;
float *vv = 0;
float a[3];
status = CV_OK;
hand_length = size.width;
hand_length2 = hand_length / 2;
threshold = (float) (size.height * 3 / 5.);
threshold2 = threshold * threshold;
/* low_count = count/nbins; */
low_count = (int) (count / 60.);
assert( points != NULL && line != NULL );
if( points == NULL || line == NULL )
return CV_NULLPTR_ERR;
assert( count > 5 );
if( count < 5 )
return CV_BADFLAG_ERR;
assert( flag == 0 || flag == 1 );
if( flag != 0 && flag != 1 )
return CV_BADFLAG_ERR;
/* create vectors */
sub = icvCreateVector_32f( 3 );
cros = icvCreateVector_32f( 3 );
if( sub == NULL || cros == NULL )
return CV_OUTOFMEM_ERR;
/* alloc memory for the point's projections on the line */
vv = (float *) cvAlloc( count * sizeof( float ));
if( vv == NULL )
return CV_OUTOFMEM_ERR;
/* alloc memory for the point's counter in the bickets */
bin_counts = (int *) cvAlloc( nbins * sizeof( int ));
if( bin_counts == NULL )
{
status = CV_OUTOFMEM_ERR;
goto M_END;
}
memset( bin_counts, 0, nbins * sizeof( int ));
cvStartReadSeq( indexs, &reader, 0 );
/* alloc memory for the temporale point's numbers */
tmp_number = (CvPoint *) cvAlloc( count * sizeof( CvPoint ));
if( tmp_number == NULL )
{
status = CV_OUTOFMEM_ERR;
goto M_END;
}
/* find min and max point's projection on the line */
vmin = 1000;
vmax = -1000;
i_point = 0;
for( i = 0; i < count; i++ )
{
/*
icvSubVector_32f ((IppmVect32f )&points[i], (IppmVect32f )&line[3], sub, 3);
icvCrossProduct2L_32f ((IppmVect32f )&line[0], sub, cros);
*/
sub[0] = points[i].x - line[3];
sub[1] = points[i].y - line[4];
sub[2] = points[i].z - line[5];
a[0] = sub[0] * line[1] - sub[1] * line[0];
a[1] = sub[1] * line[2] - sub[2] * line[1];
a[2] = sub[2] * line[0] - sub[0] * line[2];
/* if(IPPI_NORM_L22 ( cros ) < threshold2) */
if( _CV_NORM_L22( a ) < threshold2 )
{
value = (float)icvDotProduct_32f( sub, &line[0], 3 );
if( value > vmax )
vmax = value;
if( value < vmin )
vmin = value;
vv[i_point] = value;
pt = (CvPoint*)cvGetSeqElem( indexs, i );
tmp_number[i_point] = *pt;
i_point++;
}
}
/* compute the length of one bucket */
vl = vmax - vmin;
bsize = vl / nbins;
/* compute the number of points in each bucket */
for( i = 0; i < i_point; i++ )
{
l = cvRound( (vv[i] - vmin) / bsize );
bin_counts[l]++;
}
*numbers = cvCreateSeq( CV_SEQ_POINT_SET, sizeof( CvSeq ), sizeof( CvPoint ), storage );
assert( numbers != 0 );
if( numbers == NULL )
{
status = CV_OUTOFMEM_ERR;
goto M_END;
}
cvStartAppendToSeq( *numbers, &writer );
if( flag == 0 )
{
/* find the leftmost bucket */
for( l = 0; l < nbins; l++ )
{
if( bin_counts[l] > low_count )
break;
}
left = l;
/* compute center point of the left hand */
hand_left = vmin + left * bsize;
vc = hand_left + hand_length2;
hand_right = hand_left + hand_length;
}
else
{
/* find the rightmost bucket */
for( l = nbins - 1; l >= 0; l-- )
{
if( bin_counts[l] > low_count )
break;
}
right = l;
/* compute center point of the right hand */
hand_right = vmax - (nbins - right - 1) * bsize;
vc = hand_right - hand_length2;
hand_left = hand_right - hand_length;
}
icvScaleVector_32f( &line[0], sub, 3, vc );
icvAddVector_32f( &line[3], sub, (float *) center, 3 );
/* select hand's points and calculate mean value */
//ss.x = ss.y = ss.z = 0;
for( l = 0; l < i_point; l++ )
{
if( vv[l] >= hand_left && vv[l] <= hand_right )
{
CV_WRITE_SEQ_ELEM( tmp_number[l], writer );
}
}
cvEndWriteSeq( &writer );
M_END:
if( tmp_number != NULL )
cvFree( &tmp_number );
if( bin_counts != NULL )
cvFree( &bin_counts );
if( vv != NULL )
cvFree( &vv );
if( sub != NULL ) icvDeleteVector (sub);
if( cros != NULL ) icvDeleteVector (cros);
return status;
}
static CvStatus CV_STDCALL
icvFindHandRegionA( CvPoint3D32f * points, int count,
CvSeq * indexs,
float *line, CvSize2D32f size, int jc,
CvPoint3D32f * center,
CvMemStorage * storage, CvSeq ** numbers )
{
/* IppmVect32f sub, cros; */
float *sub, *cros;
float eps = (float) 0.01;
CvSeqWriter writer;
CvSeqReader reader;
CvStatus status;
float gor[3] = { 1, 0, 0 };
float ver[3] = { 0, 1, 0 };
int nbins = 20, i, l, i_point, left, right, jmin, jmax, jl;
int j_left, j_right;
int *bin_counts = 0; // pointer to the point's counter in the bickets
// int *bin_countsj = 0; // pointer to the index's counter in the bickets
int low_count; // low threshold
CvPoint *tmp_number = 0, *pt;
float value, vmin, vmax, vl, bsize, bsizej, vc, vcl, vcr;
double v_ver, v_gor;
float hand_length, hand_length2, hand_left, hand_right;
float threshold, threshold2;
float *vv = 0;
float a[3];
char log;
status = CV_OK;
hand_length = size.width;
hand_length2 = hand_length / 2;
threshold = (float) (size.height * 3 / 5.);
threshold2 = threshold * threshold;
/* low_count = count/nbins; */
low_count = (int) (count / 60.);
assert( points != NULL && line != NULL );
if( points == NULL || line == NULL )
return CV_NULLPTR_ERR;
assert( count > 5 );
if( count < 5 )
return CV_BADFLAG_ERR;
/* create vectors */
sub = icvCreateVector_32f( 3 );
cros = icvCreateVector_32f( 3 );
if( sub == NULL || cros == NULL )
return CV_OUTOFMEM_ERR;
/* alloc memory for the point's projections on the line */
vv = (float *) cvAlloc( count * sizeof( float ));
if( vv == NULL )
return CV_OUTOFMEM_ERR;
/* alloc memory for the point's counter in the bickets */
bin_counts = (int *) cvAlloc( nbins * sizeof( int ));
if( bin_counts == NULL )
{
status = CV_OUTOFMEM_ERR;
goto M_END;
}
memset( bin_counts, 0, nbins * sizeof( int ));
/* alloc memory for the point's counter in the bickets */
// bin_countsj = (int*) icvAlloc(nbins*sizeof(int));
// if(bin_countsj == NULL) {status = CV_OUTOFMEM_ERR; goto M_END;}
// memset(bin_countsj,0,nbins*sizeof(int));
cvStartReadSeq( indexs, &reader, 0 );
/* alloc memory for the temporale point's numbers */
tmp_number = (CvPoint *) cvAlloc( count * sizeof( CvPoint ));
if( tmp_number == NULL )
{
status = CV_OUTOFMEM_ERR;
goto M_END;
}
/* find min and max point's projection on the line */
vmin = 1000;
vmax = -1000;
jmin = 1000;
jmax = -1000;
i_point = 0;
for( i = 0; i < count; i++ )
{
/*
icvSubVector_32f ((IppmVect32f )&points[i], (IppmVect32f )&line[3], sub, 3);
icvCrossProduct2L_32f ((IppmVect32f )&line[0], sub, cros);
*/
sub[0] = points[i].x - line[3];
sub[1] = points[i].y - line[4];
sub[2] = points[i].z - line[5];
// if(fabs(sub[0])<eps||fabs(sub[1])<eps||fabs(sub[2])<eps) continue;
a[0] = sub[0] * line[1] - sub[1] * line[0];
a[1] = sub[1] * line[2] - sub[2] * line[1];
a[2] = sub[2] * line[0] - sub[0] * line[2];
v_gor = icvDotProduct_32f( gor, &line[0], 3 );
v_ver = icvDotProduct_32f( ver, &line[0], 3 );
if( v_ver > v_gor )
log = true;
else
log = false;
/* if(IPPI_NORM_L22 ( cros ) < threshold2) */
/*
if(fabs(a[0])<eps && fabs(a[1])<eps && fabs(a[2])<eps)
{
icvDotProduct_32f( sub, &line[0], 3, &value);
if(value > vmax) vmax = value;
if(value < vmin) vmin = value;
vv[i_point] = value;
pt = (CvPoint* )icvGetSeqElem ( indexs, i, 0);
if(pt->x > jmax) jmax = pt->x;
if(pt->x < jmin) jmin = pt->x;
tmp_number[i_point] = *pt;
i_point++;
}
else
*/
{
if( _CV_NORM_L32( a ) < threshold2 )
{
value = (float)icvDotProduct_32f( sub, &line[0], 3 );
if( value > vmax )
vmax = value;
if( value < vmin )
vmin = value;
vv[i_point] = value;
pt = (CvPoint*)cvGetSeqElem( indexs, i );
if( !log )
{
if( pt->x > jmax )
jmax = pt->x;
if( pt->x < jmin )
jmin = pt->x;
}
else
{
if( pt->y > jmax )
jmax = pt->y;
if( pt->y < jmin )
jmin = pt->y;
}
tmp_number[i_point] = *pt;
i_point++;
}
}
}
/* compute the length of one bucket along the line */
vl = vmax - vmin;
/* examining on the arm's existence */
if( vl < eps )
{
*numbers = NULL;
status = CV_OK;
goto M_END;
}
bsize = vl / nbins;
/* compute the number of points in each bucket along the line */
for( i = 0; i < i_point; i++ )
{
l = cvRound( (vv[i] - vmin) / bsize );
bin_counts[l]++;
}
/* compute the length of one bucket along the X axe */
jl = jmax - jmin;
if( jl <= 1 )
{
*numbers = NULL;
status = CV_OK;
goto M_END;
}
bsizej = (float) (jl / (nbins + 0.));
/* compute the number of points in each bucket along the X axe */
// for(i=0;i<i_point;i++)
// {
// l = cvRound((tmp_number[i].x - jmin)/bsizej);
// bin_countsj[l]++;
// }
left = right = -1;
/* find the leftmost and the rightmost buckets */
for( l = 0; l < nbins; l++ )
{
if( bin_counts[l] > low_count && left == -1 )
left = l;
else if( bin_counts[l] > low_count && left >= 0 )
right = l;
}
/* compute center point of the left hand */
if( left == -1 && right == -1 )
{
*numbers = NULL;
status = CV_OK;
goto M_END;
}
hand_left = vmin + left * bsize;
j_left = (int) (jmin + left * bsizej);
vcl = hand_left + hand_length2;
/* compute center point of the right hand */
hand_right = vmax - (nbins - right - 1) * bsize;
vcr = hand_right - hand_length2;
j_right = (int) (jmax - (nbins - right - 1) * bsizej);
j_left = abs( j_left - jc );
j_right = abs( j_right - jc );
if( j_left <= j_right )
{
hand_right = hand_left + hand_length;
vc = vcl;
}
else
{
hand_left = hand_right - hand_length;
vc = vcr;
}
icvScaleVector_32f( &line[0], sub, 3, vc );
icvAddVector_32f( &line[3], sub, (float *) center, 3 );
/* select hand's points and calculate mean value */
*numbers = cvCreateSeq( CV_SEQ_POINT_SET, sizeof( CvSeq ), sizeof( CvPoint ), storage );
assert( *numbers != 0 );
if( *numbers == NULL )
{
status = CV_OUTOFMEM_ERR;
goto M_END;
}
cvStartAppendToSeq( *numbers, &writer );
for( l = 0; l < i_point; l++ )
{
if( vv[l] >= hand_left && vv[l] <= hand_right )
{
CV_WRITE_SEQ_ELEM( tmp_number[l], writer );
}
}
cvEndWriteSeq( &writer );
M_END:
if( tmp_number != NULL )
cvFree( &tmp_number );
// if(bin_countsj != NULL) cvFree( &bin_countsj );
if( bin_counts != NULL )
cvFree( &bin_counts );
if( vv != NULL )
cvFree( &vv );
if( sub != NULL ) icvDeleteVector (sub);
if( cros != NULL ) icvDeleteVector (cros);
return status;
}
CvStatus icvEstimate1DHMMStateParams(CvImgObsInfo** obs_info_array, int num_img, CvEHMM* hmm)
{
/* compute gamma, weights, means, vars */
int k, i, j, m;
int counter = 0;
int total = 0;
int vect_len = obs_info_array[0]->obs_size;
float start_log_var_val = LN2PI * vect_len;
CvVect32f tmp_vect = icvCreateVector_32f( vect_len );
CvEHMMState* first_state = hmm->u.state;
assert( sizeof(float) == sizeof(int) );
total+= hmm->num_states;
/***************Gamma***********************/
/* initialize gamma */
for( i = 0; i < total; i++ )
{
for (m = 0; m < first_state[i].num_mix; m++)
{
((int*)(first_state[i].weight))[m] = 0;
}
}
/* maybe gamma must be computed in mixsegm process ?? */
/* compute gamma */
counter = 0;
for (k = 0; k < num_img; k++)
{
CvImgObsInfo* info = obs_info_array[k];
int num_obs = info->obs_y * info->obs_x;
for (i = 0; i < num_obs; i++)
{
int state, mixture;
state = info->state[i];
mixture = info->mix[i];
/* computes gamma - number of observations corresponding
to every mixture of every state */
((int*)(first_state[state].weight))[mixture] += 1;
}
}
/***************Mean and Var***********************/
/* compute means and variances of every item */
/* initially variance placed to inv_var */
/* zero mean and variance */
for (i = 0; i < total; i++)
{
memset( (void*)first_state[i].mu, 0, first_state[i].num_mix * vect_len *
sizeof(float) );
memset( (void*)first_state[i].inv_var, 0, first_state[i].num_mix * vect_len *
sizeof(float) );
}
/* compute sums */
for (i = 0; i < num_img; i++)
{
CvImgObsInfo* info = obs_info_array[i];
int total_obs = info->obs_x;// * info->obs_y;
float* vector = info->obs;
for (j = 0; j < total_obs; j++, vector+=vect_len )
{
int state = info->state[j];
int mixture = info->mix[j];
CvVect32f mean = first_state[state].mu + mixture * vect_len;
CvVect32f mean2 = first_state[state].inv_var + mixture * vect_len;
icvAddVector_32f( mean, vector, mean, vect_len );
icvAddSquare_32f_C1IR( vector, vect_len * sizeof(float),
mean2, vect_len * sizeof(float), cvSize(vect_len, 1) );
}
}
/*compute the means and variances */
/* assume gamma already computed */
counter = 0;
for (i = 0; i < total; i++)
{
CvEHMMState* state = &(first_state[i]);
for (m = 0; m < state->num_mix; m++)
{
int k;
CvVect32f mu = state->mu + m * vect_len;
CvVect32f invar = state->inv_var + m * vect_len;
if ( ((int*)state->weight)[m] > 1)
{
float inv_gamma = 1.f/((int*)(state->weight))[m];
icvScaleVector_32f( mu, mu, vect_len, inv_gamma);
icvScaleVector_32f( invar, invar, vect_len, inv_gamma);
}
icvMulVectors_32f(mu, mu, tmp_vect, vect_len);
icvSubVector_32f( invar, tmp_vect, invar, vect_len);
/* low bound of variance - 0.01 (Ara's experimental result) */
for( k = 0; k < vect_len; k++ )
{
invar[k] = (invar[k] > 0.01f) ? invar[k] : 0.01f;
}
/* compute log_var */
state->log_var_val[m] = start_log_var_val;
for( k = 0; k < vect_len; k++ )
{
state->log_var_val[m] += (float)log( invar[k] );
}
state->log_var_val[m] *= 0.5;
/* compute inv_var = 1/sqrt(2*variance) */
icvScaleVector_32f(invar, invar, vect_len, 2.f );
icvbInvSqrt_32f(invar, invar, vect_len );
}
}
/***************Weights***********************/
/* normilize gammas - i.e. compute mixture weights */
//compute weights
for (i = 0; i < total; i++)
{
int gamma_total = 0;
float norm;
for (m = 0; m < first_state[i].num_mix; m++)
{
gamma_total += ((int*)(first_state[i].weight))[m];
}
norm = gamma_total ? (1.f/(float)gamma_total) : 0.f;
for (m = 0; m < first_state[i].num_mix; m++)
{
first_state[i].weight[m] = ((int*)(first_state[i].weight))[m] * norm;
}
}
icvDeleteVector( tmp_vect);
return CV_NO_ERR;
}
/* for now this function works bad with singular cases
You can see in the code, that when some troubles with
matrices or some variables occur -
box filled with zero values is returned.
However in general function works fine.
*/
static CvStatus icvFitEllipse_32f( CvSeq* points, CvBox2D* box )
{
CvStatus status = CV_OK;
float u[6];
CvMatr32f D = 0;
float S[36]; /* S = D' * D */
float C[36];
float INVQ[36];
/* transposed eigenvectors */
float INVEIGV[36];
/* auxulary matrices */
float TMP1[36];
float TMP2[36];
int i, index = -1;
float eigenvalues[6];
float a, b, c, d, e, f;
float offx, offy;
float *matr;
int n = points->total;
CvSeqReader reader;
int is_float = CV_SEQ_ELTYPE(points) == CV_32FC2;
CvMat _S, _EIGVECS, _EIGVALS;
/* create matrix D of input points */
D = icvCreateMatrix_32f( 6, n );
offx = offy = 0;
cvStartReadSeq( points, &reader );
/* shift all points to zero */
for( i = 0; i < n; i++ )
{
if( !is_float )
{
offx += (float)((CvPoint*)reader.ptr)->x;
offy += (float)((CvPoint*)reader.ptr)->y;
}
else
{
offx += ((CvPoint2D32f*)reader.ptr)->x;
offy += ((CvPoint2D32f*)reader.ptr)->y;
}
CV_NEXT_SEQ_ELEM( points->elem_size, reader );
}
c = 1.f / n;
offx *= c;
offy *= c;
/* fill matrix rows as (x*x, x*y, y*y, x, y, 1 ) */
matr = D;
for( i = 0; i < n; i++ )
{
float x, y;
if( !is_float )
{
x = (float)((CvPoint*)reader.ptr)->x - offx;
y = (float)((CvPoint*)reader.ptr)->y - offy;
}
else
{
x = ((CvPoint2D32f*)reader.ptr)->x - offx;
y = ((CvPoint2D32f*)reader.ptr)->y - offy;
}
CV_NEXT_SEQ_ELEM( points->elem_size, reader );
matr[0] = x * x;
matr[1] = x * y;
matr[2] = y * y;
matr[3] = x;
matr[4] = y;
matr[5] = 1.f;
matr += 6;
}
/* compute S */
icvMulTransMatrixR_32f( D, 6, n, S );
/* fill matrix C */
icvSetZero_32f( C, 6, 6 );
C[2] = 2.f; //icvSetElement_32f( C, 6, 6, 0, 2, 2.f );
C[7] = -1.f; //icvSetElement_32f( C, 6, 6, 1, 1, -1.f );
C[12] = 2.f; //icvSetElement_32f( C, 6, 6, 2, 0, 2.f );
/* find eigenvalues */
//status1 = icvJacobiEigens_32f( S, INVEIGV, eigenvalues, 6, 0.f );
//assert( status1 == CV_OK );
_S = cvMat( 6, 6, CV_32F, S );
_EIGVECS = cvMat( 6, 6, CV_32F, INVEIGV );
_EIGVALS = cvMat( 6, 1, CV_32F, eigenvalues );
cvEigenVV( &_S, &_EIGVECS, &_EIGVALS, 0 );
//avoid troubles with small negative values
for( i = 0; i < 6; i++ )
eigenvalues[i] = (float)fabs(eigenvalues[i]);
cvbSqrt( eigenvalues, eigenvalues, 6 );
cvbInvSqrt( eigenvalues, eigenvalues, 6 );
for( i = 0; i < 6; i++ )
icvScaleVector_32f( &INVEIGV[i * 6], &INVEIGV[i * 6], 6, eigenvalues[i] );
// INVQ = transp(INVEIGV) * INVEIGV
icvMulTransMatrixR_32f( INVEIGV, 6, 6, INVQ );
/* create matrix INVQ*C*INVQ */
icvMulMatrix_32f( INVQ, 6, 6, C, 6, 6, TMP1 );
icvMulMatrix_32f( TMP1, 6, 6, INVQ, 6, 6, TMP2 );
/* find its eigenvalues and vectors */
//status1 = icvJacobiEigens_32f( TMP2, INVEIGV, eigenvalues, 6, 0.f );
//assert( status1 == CV_OK );
_S = cvMat( 6, 6, CV_32F, TMP2 );
cvEigenVV( &_S, &_EIGVECS, &_EIGVALS, 0 );
/* search for positive eigenvalue */
for( i = 0; i < 3; i++ )
{
if( eigenvalues[i] > 0 )
{
index = i;
break;
}
}
/* only 3 eigenvalues must be not zero
and only one of them must be positive
if it is not true - return zero result
*/
if( index == -1 )
{
box->center.x = box->center.y =
box->size.width = box->size.height =
box->angle = 0.f;
goto error;
}
/* now find truthful eigenvector */
icvTransformVector_32f( INVQ, &INVEIGV[index * 6], u, 6, 6 );
/* extract vector components */
a = u[0];
b = u[1];
c = u[2];
d = u[3];
e = u[4];
f = u[5];
{
/* extract ellipse axes from above values */
/*
1) find center of ellipse
it satisfy equation
| a b/2 | * | x0 | + | d/2 | = |0 |
| b/2 c | | y0 | | e/2 | |0 |
*/
float x0, y0;
float idet = 1.f / (a * c - b * b * 0.25f);
/* we must normalize (a b c d e f ) to fit (4ac-b^2=1) */
float scale = cvSqrt( 0.25f * idet );
if (!scale)
{
box->center.x = box->center.y =
box->size.width = box->size.height =
box->angle = 0.f;
goto error;
}
a *= scale;
b *= scale;
c *= scale;
d *= scale;
e *= scale;
f *= scale;
//x0 = box->center.x = (-d * c * 0.5f + e * b * 0.25f) * 4.f;
//y0 = box->center.y = (-a * e * 0.5f + d * b * 0.25f) * 4.f;
x0 = box->center.x = (-d * c + e * b * 0.5f) * 2.f;
y0 = box->center.y = (-a * e + d * b * 0.5f) * 2.f;
/* offset ellipse to (x0,y0) */
/* new f == F(x0,y0) */
f += a * x0 * x0 + b * x0 * y0 + c * y0 * y0 + d * x0 + e * y0;
if (!f)
{
box->center.x = box->center.y =
box->size.width = box->size.height =
box->angle = 0.f;
goto error;
}
scale = -1.f / f;
/* normalize to f = 1 */
a *= scale;
b *= scale;
c *= scale;
}
/* recover center */
box->center.x += offx;
box->center.y += offy;
/* extract axis of ellipse */
/* one more eigenvalue operation */
TMP1[0] = a;
TMP1[1] = TMP1[2] = b * 0.5f;
TMP1[3] = c;
//status1 = icvJacobiEigens_32f( TMP1, INVEIGV, eigenvalues, 2, 0.f );
//assert( status1 == CV_OK );
_S = cvMat( 2, 2, CV_32F, TMP1 );
_EIGVECS = cvMat( 2, 2, CV_32F, INVEIGV );
_EIGVALS = cvMat( 2, 1, CV_32F, eigenvalues );
cvEigenVV( &_S, &_EIGVECS, &_EIGVALS, 0 );
/* exteract axis length from eigenvectors */
box->size.height = 2 * cvInvSqrt( eigenvalues[0] );
box->size.width = 2 * cvInvSqrt( eigenvalues[1] );
if ( !(box->size.height && box->size.width) )
{
assert(0);
}
/* calc angle */
box->angle = cvFastArctan( INVEIGV[3], INVEIGV[2] );
error:
if( D )
icvDeleteMatrix( D );
return status;
}
