tracker/pt: add threshold slider state description

Isolate point radius code and reuse it.

3 files changed, 60 insertions, 28 deletions

diff --git a/tracker-pt/FTNoIR_PT_Controls.ui b/tracker-pt/FTNoIR_PT_Controls.ui
index 1132d156..ac85b2cb 100644
--- a/tracker-pt/FTNoIR_PT_Controls.ui
+++ b/tracker-pt/FTNoIR_PT_Controls.ui
@@ -9,8 +9,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>412</width>
-    <height>616</height>
+    <width>411</width>
+    <height>630</height>
    </rect>
   </property>
   <property name="sizePolicy">
@@ -458,8 +458,8 @@
           <string>Point extraction</string>
          </property>
          <layout class="QGridLayout" name="gridLayout_7">
-          <item row="3" column="0">
-           <widget class="QLabel" name="label_8">
+          <item row="1" column="0">
+           <widget class="QLabel" name="label">
             <property name="sizePolicy">
              <sizepolicy hsizetype="Preferred" vsizetype="Maximum">
               <horstretch>0</horstretch>
@@ -467,15 +467,15 @@
              </sizepolicy>
             </property>
             <property name="text">
-             <string>Max size</string>
+             <string>Threshold</string>
             </property>
             <property name="buddy">
-             <cstring>maxdiam_spin</cstring>
+             <cstring>threshold_slider</cstring>
             </property>
            </widget>
           </item>
-          <item row="1" column="0">
-           <widget class="QLabel" name="label">
+          <item row="3" column="0">
+           <widget class="QLabel" name="label_7">
             <property name="sizePolicy">
              <sizepolicy hsizetype="Preferred" vsizetype="Maximum">
               <horstretch>0</horstretch>
@@ -483,15 +483,15 @@
              </sizepolicy>
             </property>
             <property name="text">
-             <string>Threshold</string>
+             <string>Min size</string>
             </property>
             <property name="buddy">
-             <cstring>threshold_slider</cstring>
+             <cstring>mindiam_spin</cstring>
             </property>
            </widget>
           </item>
-          <item row="2" column="0">
-           <widget class="QLabel" name="label_7">
+          <item row="4" column="0">
+           <widget class="QLabel" name="label_8">
             <property name="sizePolicy">
              <sizepolicy hsizetype="Preferred" vsizetype="Maximum">
               <horstretch>0</horstretch>
@@ -499,10 +499,10 @@
              </sizepolicy>
             </property>
             <property name="text">
-             <string>Min size</string>
+             <string>Max size</string>
             </property>
             <property name="buddy">
-             <cstring>mindiam_spin</cstring>
+             <cstring>maxdiam_spin</cstring>
             </property>
            </widget>
           </item>
@@ -537,8 +537,8 @@
             </property>
            </widget>
           </item>
-          <item row="0" column="0">
-           <widget class="QLabel" name="label_11">
+          <item row="0" column="1">
+           <widget class="QCheckBox" name="auto_threshold">
             <property name="sizePolicy">
              <sizepolicy hsizetype="Preferred" vsizetype="Maximum">
               <horstretch>0</horstretch>
@@ -546,12 +546,12 @@
              </sizepolicy>
             </property>
             <property name="text">
-             <string>Automatic threshold</string>
+             <string>Enable, slider sets point size</string>
             </property>
            </widget>
           </item>
-          <item row="0" column="1">
-           <widget class="QCheckBox" name="auto_threshold">
+          <item row="0" column="0">
+           <widget class="QLabel" name="label_11">
             <property name="sizePolicy">
              <sizepolicy hsizetype="Preferred" vsizetype="Maximum">
               <horstretch>0</horstretch>
@@ -559,11 +559,11 @@
              </sizepolicy>
             </property>
             <property name="text">
-             <string>Enable, slider sets point size</string>
+             <string>Automatic threshold</string>
             </property>
            </widget>
           </item>
-          <item row="3" column="1">
+          <item row="4" column="1">
            <widget class="QDoubleSpinBox" name="maxdiam_spin">
             <property name="sizePolicy">
              <sizepolicy hsizetype="Preferred" vsizetype="Maximum">
@@ -585,7 +585,7 @@
             </property>
            </widget>
           </item>
-          <item row="2" column="1">
+          <item row="3" column="1">
            <widget class="QDoubleSpinBox" name="mindiam_spin">
             <property name="sizePolicy">
              <sizepolicy hsizetype="Preferred" vsizetype="Maximum">
@@ -607,6 +607,26 @@
             </property>
            </widget>
           </item>
+          <item row="2" column="1">
+           <widget class="QLabel" name="threshold_value_display">
+            <property name="sizePolicy">
+             <sizepolicy hsizetype="Minimum" vsizetype="Maximum">
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
+             </sizepolicy>
+            </property>
+            <property name="text">
+             <string/>
+            </property>
+           </widget>
+          </item>
+          <item row="2" column="0">
+           <widget class="QLabel" name="label_14">
+            <property name="text">
+             <string>Value</string>
+            </property>
+           </widget>
+          </item>
          </layout>
         </widget>
        </item>
diff --git a/tracker-pt/point_extractor.cpp b/tracker-pt/point_extractor.cpp
index 9030b520..adb23d52 100644
--- a/tracker-pt/point_extractor.cpp
+++ b/tracker-pt/point_extractor.cpp
@@ -101,6 +101,18 @@ void PointExtractor::separate_channels(cv::Mat const& orig, const int* order, in
         ch[k].convertTo(ch_float[k], CV_32F);
 }
 
+double PointExtractor::threshold_radius_value(int w, int h, int threshold)
+{
+    double cx = w / 640., cy = h / 480.;
+
+    const double min_radius = 1.75 * cx;
+    const double max_radius = 15 * cy;
+
+    const double radius = std::fmax(0., (max_radius-min_radius) * threshold / 255 + min_radius);
+
+    return radius;
+}
+
 void PointExtractor::extract_points(const cv::Mat& frame, cv::Mat& preview_frame, std::vector<vec2>& points)
 {
     using std::sqrt;
@@ -122,7 +134,7 @@ void PointExtractor::extract_points(const cv::Mat& frame, cv::Mat& preview_frame
     case pt_color_floppy_filter:
     {
         // weight for blue color
-        static constexpr float B = .8;
+        static constexpr float B = .667;
 
         static constexpr int from_to[] = {
             0, 0,
@@ -162,6 +174,8 @@ void PointExtractor::extract_points(const cv::Mat& frame, cv::Mat& preview_frame
         break;
     }
 
+    //cv::imshow("capture", frame_gray);
+    //cv::waitKey(1);
 
     const double region_size_min = s.min_point_size;
     const double region_size_max = s.max_point_size;
@@ -186,12 +200,8 @@ void PointExtractor::extract_points(const cv::Mat& frame, cv::Mat& preview_frame
                      (int const*) &hist_size,
                      &ranges);
 
-        const double cx = frame.cols / 640., cy = frame.rows / 480.;
-
-        const double min_radius = 1.75 * cx;
-        const double max_radius = 15 * cy;
+        const double radius = threshold_radius_value(frame.cols, frame.rows, s.threshold);
 
-        const double radius = fmax(0., (max_radius-min_radius) * s.threshold / 255 + min_radius);
         float const* restrict_ptr ptr = reinterpret_cast<float const* restrict_ptr>(hist.ptr(0));
         const unsigned area = uround(3 * M_PI * radius*radius);
         const unsigned sz = unsigned(hist.cols * hist.rows);
diff --git a/tracker-pt/point_extractor.h b/tracker-pt/point_extractor.h
index 8fd521c3..fd32e94b 100644
--- a/tracker-pt/point_extractor.h
+++ b/tracker-pt/point_extractor.h
@@ -39,6 +39,8 @@ public:
     PointExtractor();
 
     settings_pt s;
+
+    static double threshold_radius_value(int w, int h, int threshold);
 private:
     static constexpr int max_blobs = 16;