* Use `nth_element()` to find the median instead of `sort()` in `LMeDSPointSetRegistrator::run()`
* Improves performance of this part of LMedS from `n log(n)` to `n` by avoiding doing a full sort.
* Makes LMedS 2x faster for 100 points, 4x faster for 5,000 points in `EstimateAffine2D()`.
* LMedS is now never more than 2x slower than RANSAC and is faster in some cases.
else
errf = err;
CV_Assert( errf.isContinuous() && errf.type() == CV_32F && (int)errf.total() == count );
- std::sort(errf.ptr<int>(), errf.ptr<int>() + count);
-
- double median = count % 2 != 0 ?
- errf.at<float>(count/2) : (errf.at<float>(count/2-1) + errf.at<float>(count/2))*0.5;
+ std::nth_element(errf.ptr<int>(), errf.ptr<int>() + count/2, errf.ptr<int>() + count);
+ double median = errf.at<float>(count/2);
if( median < minMedian )
{