tracker/pt: fix points at (0,0) which are really NaN

Issue: #318
cf. http://forum.il2sturmovik.ru/topic/2291-open-track/page-26

1 files changed, 8 insertions, 0 deletions

diff --git a/tracker-pt/point_extractor.cpp b/tracker-pt/point_extractor.cpp
index 96c70d11..e27bd3c7 100644
--- a/tracker-pt/point_extractor.cpp
+++ b/tracker-pt/point_extractor.cpp
@@ -13,6 +13,8 @@
 #   include "opentrack-compat/timer.hpp"
 #endif
 
+#include <cmath>
+
 PointExtractor::PointExtractor()
 {
     blobs.reserve(max_blobs);
@@ -81,7 +83,13 @@ const std::vector<cv::Vec2f>& PointExtractor::extract_points(cv::Mat& frame)
 
     for (auto& c : contours)
     {
+        using std::fabs;
+
         const auto m = cv::moments(cv::Mat(c));
+
+        if (fabs(m.m00) < 1e-3)
+            continue;
+
         const cv::Vec2d pos(m.m10 / m.m00, m.m01 / m.m00);
 
         double radius;