Revert "tracker/pt: remove arbitrary min brightness threshold"

This reverts commit 8ac0471c1c0c4cdf76f696b7c3c18d1d3a776a78.

Discussion: #1381

1 files changed, 3 insertions, 2 deletions

diff --git a/tracker-pt/module/point_extractor.cpp b/tracker-pt/module/point_extractor.cpp
index 71586eb1..fbb830d3 100644
--- a/tracker-pt/module/point_extractor.cpp
+++ b/tracker-pt/module/point_extractor.cpp
@@ -220,8 +220,9 @@ void PointExtractor::threshold_image(const cv::Mat& frame_gray, cv::Mat1b& outpu
         float const* const __restrict ptr = hist.ptr<float>(0);
         const unsigned area = unsigned(iround(3 * pi * radius*radius));
         const unsigned sz = unsigned(hist.cols * hist.rows);
-        unsigned thres = 1;
-        for (unsigned i = sz-1, cnt = 0; i > 1; i--)
+        constexpr unsigned min_thres = 64;
+        unsigned thres = min_thres;
+        for (unsigned i = sz-1, cnt = 0; i > 32; i--)
         {
             cnt += (unsigned)ptr[i];
             if (cnt >= area)