tracker/pt: resize the camera feed, not the preview

This makes the point size text and point crosses not alias due to the
resize.

Due to nice pixel coordinate system, the cross-drawing lambda only needs
minimal changes.

4 files changed, 30 insertions, 36 deletions

diff --git a/tracker-pt/ftnoir_tracker_pt.cpp b/tracker-pt/ftnoir_tracker_pt.cpp
index 08bf56c6..d196b2ee 100644
--- a/tracker-pt/ftnoir_tracker_pt.cpp
+++ b/tracker-pt/ftnoir_tracker_pt.cpp
@@ -58,7 +58,6 @@ void Tracker_PT::run()
 #endif
 
     apply_settings();
-    cv::Mat frame_;
 
     while((commands & ABORT) == 0)
     {
@@ -70,17 +69,13 @@ void Tracker_PT::run()
         {
             QMutexLocker l(&camera_mtx);
             new_frame = camera.get_frame(dt, frame, cam_info);
-            if (new_frame)
-            {
-                if (frame.rows != frame_.rows || frame.cols != frame_.cols)
-                    frame_ = cv::Mat(frame.rows, frame.cols, CV_8UC3);
-            }
-            frame.copyTo(frame_);
         }
 
-        if (new_frame && !frame_.empty())
+        cv::resize(frame, preview_frame, cv::Size(preview_size.width(), preview_size.height()), 0, 0, cv::INTER_NEAREST);
+
+        if (new_frame && !frame.empty())
         {
-            point_extractor.extract_points(frame_, points);
+            point_extractor.extract_points(frame, preview_frame, points);
             point_count = points.size();
 
             f fx;
@@ -99,26 +94,20 @@ void Tracker_PT::run()
 
             auto fun = [&](const vec2& p, const cv::Scalar& color)
             {
-                using std::round;
-                using std::sqrt;
-                using std::max;
-
-                static constexpr int frame_size = 400;
-                const double size = max(1., 1.5*sqrt(frame.rows*frame.rows + frame.cols*frame.cols) / frame_size);
-                const int len = std::max(1, iround(size * 7.5));
+                static constexpr f len = 9;
 
-                cv::Point p2(int(round(p[0] * frame_.cols + frame_.cols/2)),
-                             int(round(-p[1] * frame_.cols + frame_.rows/2)));
-                cv::line(frame_,
+                cv::Point p2(iround(p[0] * preview_frame.cols + preview_frame.cols/2),
+                             iround(-p[1] * preview_frame.cols + preview_frame.rows/2));
+                cv::line(preview_frame,
                          cv::Point(p2.x - len, p2.y),
                          cv::Point(p2.x + len, p2.y),
                          color,
-                         iround(size/2));
-                cv::line(frame_,
+                         1);
+                cv::line(preview_frame,
                          cv::Point(p2.x, p2.y - len),
                          cv::Point(p2.x, p2.y + len),
                          color,
-                         iround(size/2));
+                         1);
             };
 
             for (unsigned i = 0; i < points.size(); i++)
@@ -140,7 +129,7 @@ void Tracker_PT::run()
                 fun(p_, cv::Scalar(0, 0, 255));
             }
 
-            video_widget->update_image(frame_);
+            video_widget->update_image(preview_frame);
         }
     }
     qDebug() << "pt: thread stopped";
@@ -166,12 +155,13 @@ void Tracker_PT::apply_settings()
 void Tracker_PT::start_tracker(QFrame* video_frame)
 {
     video_frame->setAttribute(Qt::WA_NativeWindow);
+    preview_size = video_frame->size();
     video_widget = qptr<cv_video_widget>(video_frame);
     layout = qptr<QHBoxLayout>(video_frame);
     layout->setContentsMargins(0, 0, 0, 0);
     layout->addWidget(video_widget.data());
     video_frame->setLayout(layout.data());
-    video_widget->resize(video_frame->width(), video_frame->height());
+    //video_widget->resize(video_frame->width(), video_frame->height());
     video_frame->show();
     start();
 }
diff --git a/tracker-pt/ftnoir_tracker_pt.h b/tracker-pt/ftnoir_tracker_pt.h
index fcf74bff..e050f4ad 100644
--- a/tracker-pt/ftnoir_tracker_pt.h
+++ b/tracker-pt/ftnoir_tracker_pt.h
@@ -26,6 +26,7 @@
 #include <QMutexLocker>
 #include <QTime>
 #include <QLayout>
+#include <QSize>
 #include <atomic>
 #include <memory>
 #include <vector>
@@ -74,9 +75,11 @@ private:
 
     settings_pt s;
     Timer time;
-    cv::Mat frame;
+    cv::Mat frame, preview_frame;
     std::vector<vec2> points;
 
+    QSize preview_size;
+
     volatile unsigned point_count;
     volatile unsigned char commands;
     volatile bool ever_success;
diff --git a/tracker-pt/point_extractor.cpp b/tracker-pt/point_extractor.cpp
index f7f63784..3109db09 100644
--- a/tracker-pt/point_extractor.cpp
+++ b/tracker-pt/point_extractor.cpp
@@ -76,7 +76,7 @@ PointExtractor::PointExtractor()
     blobs.reserve(max_blobs);
 }
 
-void PointExtractor::extract_points(cv::Mat& frame, std::vector<vec2>& points)
+void PointExtractor::extract_points(const cv::Mat& frame, cv::Mat& preview_frame, std::vector<vec2>& points)
 {
     using std::sqrt;
     using std::max;
@@ -193,19 +193,19 @@ void PointExtractor::extract_points(cv::Mat& frame, std::vector<vec2>& points)
                 blob b(radius, cv::Vec2d(m10 / N, m01 / N), N/sqrt(double(cnt)), rect);
                 blobs.push_back(b);
 
-                static constexpr int frame_size = 400;
-                const double size = std::max(1, iround(std::sqrt(frame.rows*frame.rows + frame.cols*frame.cols) / frame_size));
-
                 {
                     char buf[64];
                     sprintf(buf, "%.2fpx", radius);
-                    cv::putText(frame,
+                    static const vec2 off(10, 7.5);
+                    const f cx = preview_frame.cols / f(frame.cols),
+                            cy = preview_frame.rows / f(frame.rows);
+                    cv::putText(preview_frame,
                                 buf,
-                                cv::Point((int)round(b.pos[0]+15*size), (int)round(b.pos[1]+10*size)),
+                                cv::Point(iround(b.pos[0]*cx+off[0]), iround(b.pos[1]*cy+off[1])),
                                 cv::FONT_HERSHEY_PLAIN,
-                                size,
+                                1,
                                 cv::Scalar(0, 0, 255),
-                                iround(size));
+                                1);
                 }
 
                 if (idx >= max_blobs) goto end;
@@ -251,7 +251,7 @@ end:
     points.reserve(max_blobs);
     points.clear();
 
-    for (auto& b : blobs)
+    for (const auto& b : blobs)
     {
         // note: H/W is equal to fx/fy
 
@@ -260,7 +260,8 @@ end:
     }
 }
 
-PointExtractor::blob::blob(double radius, const cv::Vec2d& pos, double brightness, cv::Rect& rect) : radius(radius), brightness(brightness), pos(pos), rect(rect)
+PointExtractor::blob::blob(double radius, const cv::Vec2d& pos, double brightness, cv::Rect& rect) :
+    radius(radius), brightness(brightness), pos(pos), rect(rect)
 {
     //qDebug() << "radius" << radius << "pos" << pos[0] << pos[1];
 }
diff --git a/tracker-pt/point_extractor.h b/tracker-pt/point_extractor.h
index 3ad8ed52..ad02d7f8 100644
--- a/tracker-pt/point_extractor.h
+++ b/tracker-pt/point_extractor.h
@@ -27,7 +27,7 @@ public:
     // extracts points from frame and draws some processing info into frame, if draw_output is set
     // dt: time since last call in seconds
     // WARNING: returned reference is valid as long as object
-    void extract_points(cv::Mat &frame, std::vector<vec2>& points);
+    void extract_points(const cv::Mat& frame, cv::Mat& preview_frame, std::vector<vec2>& points);
     PointExtractor();
 
     settings_pt s;