inline size_t trackFeatures_deleteOOB_impl_simple_feat(
FEATLIST &trackedFeats,
const size_t img_width, const size_t img_height,
const int MIN_DIST_MARGIN_TO_STOP_TRACKING)
{
if (trackedFeats.empty()) return 0;
std::vector<size_t> survival_idxs;
const size_t N = trackedFeats.size();
// 1st: Build list of survival indexes:
survival_idxs.reserve(N);
for (size_t i=0;i<N;i++)
{
const typename FEATLIST::feature_t &ft = trackedFeats[i];
const TFeatureTrackStatus status = ft.track_status;
bool eras = (status_TRACKED!=status && status_IDLE!=status);
if (!eras)
{
// Also, check if it's too close to the image border:
const int x= ft.pt.x;
const int y= ft.pt.y;
if (x<MIN_DIST_MARGIN_TO_STOP_TRACKING || y<MIN_DIST_MARGIN_TO_STOP_TRACKING ||
x>static_cast<int>(img_width-MIN_DIST_MARGIN_TO_STOP_TRACKING) ||
y>static_cast<int>(img_height-MIN_DIST_MARGIN_TO_STOP_TRACKING))
{
eras = true;
}
}
if (!eras) survival_idxs.push_back(i);
}
// 2nd: Build updated list:
const size_t N2 = survival_idxs.size();
const size_t n_removed = N-N2;
for (size_t i=0;i<N2;i++)
{
if (survival_idxs[i]!=i)
trackedFeats[i] = trackedFeats[ survival_idxs[i] ];
}
trackedFeats.resize(N2);
return n_removed;
} // end of trackFeatures_deleteOOB
void CFeatureTracker_KL::trackFeatures_impl_templ(
const CImage &old_img,
const CImage &new_img,
FEATLIST &featureList )
{
MRPT_START
#if MRPT_HAS_OPENCV
const unsigned int window_width = extra_params.getWithDefaultVal("window_width",15);
const unsigned int window_height = extra_params.getWithDefaultVal("window_height",15);
const int LK_levels = extra_params.getWithDefaultVal("LK_levels",3);
const int LK_max_iters = extra_params.getWithDefaultVal("LK_max_iters",10);
const int LK_epsilon = extra_params.getWithDefaultVal("LK_epsilon",0.1);
const float LK_max_tracking_error = extra_params.getWithDefaultVal("LK_max_tracking_error",150.0f);
// Both images must be of the same size
ASSERT_( old_img.getWidth() == new_img.getWidth() && old_img.getHeight() == new_img.getHeight() );
const size_t img_width = old_img.getWidth();
const size_t img_height = old_img.getHeight();
const size_t nFeatures = featureList.size(); // Number of features
// Grayscale images
const CImage prev_gray(old_img, FAST_REF_OR_CONVERT_TO_GRAY);
const CImage cur_gray(new_img, FAST_REF_OR_CONVERT_TO_GRAY);
// Array conversion MRPT->OpenCV
if (nFeatures>0)
{
CvPoint2D32f *points[2];
points[0] = reinterpret_cast<CvPoint2D32f *>( mrpt_alloca(sizeof(CvPoint2D32f)*nFeatures) );
points[1] = reinterpret_cast<CvPoint2D32f *>( mrpt_alloca(sizeof(CvPoint2D32f)*nFeatures) );
std::vector<char> status(nFeatures);
for(size_t i=0;i<nFeatures;++i)
{
points[0][i].x = featureList.getFeatureX(i);
points[0][i].y = featureList.getFeatureY(i);
} // end for
// local scope for auxiliary variables around cvCalcOpticalFlowPyrLK()
const IplImage *prev_gray_ipl = prev_gray.getAs<IplImage>();
const IplImage *cur_gray_ipl = cur_gray.getAs<IplImage>();
// Pyramids
// JL: It seems that cache'ing the pyramids of previous images doesn't really improve the efficiency (!?!?)
IplImage* pPyr = NULL;
IplImage* cPyr = NULL;
int flags = 0;
float* track_error = reinterpret_cast<float*>( mrpt_alloca(sizeof(float)*nFeatures) );
cvCalcOpticalFlowPyrLK(prev_gray_ipl, cur_gray_ipl, pPyr, cPyr,
&points[0][0], &points[1][0], nFeatures, cvSize( window_width, window_height ), LK_levels, &status[0], track_error,
cvTermCriteria(CV_TERMCRIT_ITER|CV_TERMCRIT_EPS,LK_max_iters,LK_epsilon), flags );
cvReleaseImage( &pPyr );
cvReleaseImage( &cPyr );
for(size_t i=0;i<nFeatures;++i)
{
const bool trck_err_too_large = track_error[i]>LK_max_tracking_error;
if( status[i] == 1 &&
!trck_err_too_large &&
points[1][i].x > 0 && points[1][i].y > 0 &&
points[1][i].x < img_width && points[1][i].y < img_height )
{
// Feature could be tracked
featureList.setFeatureXf(i, points[1][i].x );
featureList.setFeatureYf(i, points[1][i].y );
featureList.setTrackStatus(i, status_TRACKED );
} // end if
else // Feature could not be tracked
{
featureList.setFeatureX(i,-1);
featureList.setFeatureY(i,-1);
featureList.setTrackStatus(i, trck_err_too_large ? status_LOST : status_OOB );
} // end else
} // end for
mrpt_alloca_free( points[0] );
mrpt_alloca_free( points[1] );
mrpt_alloca_free( track_error );
// In case it needs to rebuild a kd-tree or whatever
featureList.mark_as_outdated();
}
#else
THROW_EXCEPTION("The MRPT has been compiled with MRPT_HAS_OPENCV=0 !");
#endif
MRPT_END
} // end trackFeatures