void R2RegionCoverer::getCovering( const R2Region& region, vector<GeoHash>* cover ) {
// Strategy: Start with the full plane. Discard any
// that do not intersect the shape. Then repeatedly choose the
// largest cell that intersects the shape and subdivide it.
//
// _result contains the cells that will be part of the output, while the
// queue contains cells that we may still subdivide further. Cells that
// are entirely contained within the region are immediately added to the
// output, while cells that do not intersect the region are immediately
// discarded. Therefore the queue only contains cells that partially
// intersect the region. Candidates are prioritized first according to
// cell size (larger cells first), then by the number of intersecting
// children they have (fewest children first), and then by the number of
// fully contained children (fewest children first).
verify(_minLevel <= _maxLevel);
dassert(_candidateQueue->empty());
dassert(_results->empty());
_region = ®ion;
getInitialCandidates();
while(!_candidateQueue->empty()) {
Candidate* candidate = _candidateQueue->top().second; // Owned
_candidateQueue->pop();
LOG(3) << "Pop: " << candidate->cell;
// Try to expand this cell into its children
if (candidate->cell.getBits() < _minLevel ||
candidate->numChildren == 1 ||
(int)_results->size() +
(int)_candidateQueue->size() +
candidate->numChildren <= _maxCells) {
for (int i = 0; i < candidate->numChildren; i++) {
addCandidate(candidate->children[i]);
}
deleteCandidate(candidate, false);
} else {
// Reached max cells. Move all candidates from the queue into results.
candidate->isTerminal = true;
addCandidate(candidate);
}
LOG(3) << "Queue: " << _candidateQueue->size();
}
_region = NULL;
cover->swap(*_results);
}
std::vector<PipelineGrid> GridFitter::fitGrid(const Tag& tag, const TagCandidate &candidate)
{
#ifdef DEBUG_GRIDFITTER
cv::destroyAllWindows();
#endif
const Ellipse& ellipse_orig = candidate.getEllipse();
// region of interest of tag candidate
const cv::Size2i roiSize = tag.getRoi().size();
cv::Mat roi;
tag.getRepresentations().clahe.copyTo(roi);
cv::Mat binarizedROI(roiSize, CV_8UC1);
cv::adaptiveThreshold(roi, binarizedROI, 255, cv::ADAPTIVE_THRESH_GAUSSIAN_C,
cv::THRESH_BINARY, _settings.get_adaptive_block_size(),
_settings.get_adaptive_c());
cv::Mat blurredRoi;
cv::GaussianBlur(roi, blurredRoi, cv::Size(3, 3), 0, 0, cv::BORDER_DEFAULT);
auto getSobel = [&](const int dx, const int dy) {
cv::Mat sobelImg;
cv::Scharr(blurredRoi, sobelImg, CV_32F, dx, dy);
static const double ksize = 3.;
const double denom = std::pow(2., ksize * 2. - dx - dy - 2);
sobelImg.convertTo(sobelImg, CV_8UC1, 1. / (2. * denom), 255. / 2.);
return sobelImg;
};
cv::Mat edgeRoiX = getSobel(1, 0);
cv::Mat edgeRoiY = getSobel(0, 1);
// TODO: constant/setting for axis border
// TODO: add sanity checks
const cv::Mat ellipseMask = candidate.getEllipse().getMask(cv::Size(10, 10));
cv::Mat equalizedRoi;
roi.copyTo(equalizedRoi, ellipseMask);
cv::equalizeHist(equalizedRoi, roi);
// get initial candidates using brute force search over small number of
// rotations and position offsets
candidate_set gridCandidates = getInitialCandidates(binarizedROI, edgeRoiX, edgeRoiY, ellipse_orig, roi);
#ifdef DEBUG_GRIDFITTER
visualizeDebug(gridCandidates, roi, roiSize, edgeRoiX, edgeRoiY, tag, binarizedROI, "candidate", _settings.get_gradient_num_initial());
#endif
// optimize best candidates using gradient descent
GradientDescent optimizer(gridCandidates, roi, binarizedROI, edgeRoiX, edgeRoiY, _settings_cache);
optimizer.optimize();
const candidate_set& bestGrids = optimizer.getBestGrids();
#ifdef DEBUG_GRIDFITTER
std::cout << "min initial candidate error: " << gridCandidates.begin()->error << std::endl;
std::cout << "min final candidate error: " << bestGrids.begin()->error << std::endl;
visualizeDebug(bestGrids, roi, roiSize, edgeRoiX, edgeRoiY, tag, binarizedROI, "best fit", _settings.get_gradient_num_results());
#endif
// return the settings.numResults best candidates
std::vector<PipelineGrid> results;
{
const size_t to = std::min(_settings.get_gradient_num_results(), bestGrids.size());
size_t idx = 0;
for (candidate_t const& gridCandidate : bestGrids) {
Util::gridconfig_t const& config = gridCandidate.config;
results.emplace_back(config.center + tag.getRoi().tl(), config.radius, config.angle_z,
config.angle_y, config.angle_x, gridCandidate.error);
++idx;
if (idx == to) break;
}
}
return results;
}
