tracker/pt: adjust auto threshold max pixel value

The confusion stems from the max slider value. It's 255, not 100 as is
the default. Max pixel count change to 20 was confused as we'll counting
area and not radius here. Taking into account that the value was divided
by 100 previously, it's bit less than the previous one but not as
confused as then.

Reported-by: @MathijsG
Issue: #355

1 files changed, 2 insertions, 2 deletions

diff --git a/tracker-pt/point_extractor.cpp b/tracker-pt/point_extractor.cpp
index 25b825fd..be1cd59c 100755
--- a/tracker-pt/point_extractor.cpp
+++ b/tracker-pt/point_extractor.cpp
@@ -116,8 +116,8 @@ const std::vector<cv::Vec2f>& PointExtractor::extract_points(cv::Mat& frame)
         const int sz = hist.cols * hist.rows;
         int val = 0;
         int cnt = 0;
-        constexpr int min_pixels = 20;
-        const auto pixels_to_include = std::max<int>(0, min_pixels * s.threshold/100.);
+        constexpr int min_pixels = 400;
+        const int pixels_to_include = std::max<int>(0, min_pixels * s.threshold / 255);
         auto ptr = reinterpret_cast<const float*>(hist.ptr(0));
         for (int i = sz-1; i >= 0; i--)
         {