void GridAdaptedFeatureDetector::detectImpl(const Mat& image, const Mat& mask,
vector<KeyPoint> &keypoints) const {
keypoints.clear();
keypoints.reserve(maxTotalKeypoints);
int maxPerCell = maxTotalKeypoints / (gridRows * gridCols);
for (int i = 0; i < gridRows; ++i) {
Range row_range((i * image.rows) / gridRows, ((i + 1)*image.rows) / gridRows);
for (int j = 0; j < gridCols; ++j) {
Range col_range((j * image.cols) / gridCols, ((j + 1)*image.cols) / gridCols);
Mat sub_image = image(row_range, col_range);
Mat sub_mask;
if (!mask.empty()) {
sub_mask = mask(row_range, col_range);
}
vector<KeyPoint> sub_keypoints;
detector->detect(sub_image, sub_keypoints, sub_mask);
keepStrongest(maxPerCell, sub_keypoints);
for (std::vector<cv::KeyPoint>::iterator it = sub_keypoints.begin(), end = sub_keypoints.end();
it != end; ++it) {
it->pt.x += col_range.start;
it->pt.y += row_range.start;
}
keypoints.insert(keypoints.end(), sub_keypoints.begin(), sub_keypoints.end());
}
}
}
worksheet::const_iterator worksheet::cbegin() const
{
auto dimensions = calculate_dimension();
cell_reference top_right(dimensions.get_bottom_right().get_column_index(), dimensions.get_top_left().get_row());
range_reference row_range(dimensions.get_top_left(), top_right);
return const_iterator(*this, row_range, major_order::row);
}
