Easy Tracker: Deleting legacy point extractor. Various clean-up. Head center preview now working.

12 files changed, 68 insertions, 575 deletions

diff --git a/tracker-easy/cv-point-extractor.cpp b/tracker-easy/cv-point-extractor.cpp
index 42f1a06b..7c0b00b5 100644
--- a/tracker-easy/cv-point-extractor.cpp
+++ b/tracker-easy/cv-point-extractor.cpp
@@ -30,19 +30,21 @@ CvPointExtractor::CvPointExtractor(const QString& module_name) : s(module_name)
 }
 
 
-void CvPointExtractor::extract_points(const cv::Mat& frame, cv::Mat& aPreview, std::vector<vec2>& points, std::vector<vec2>& imagePoints)
+void CvPointExtractor::extract_points(const cv::Mat& frame, cv::Mat* aPreview, std::vector<vec2>& aPoints)
 {
 
     // Contours detection
     std::vector<std::vector<cv::Point> > contours;
     cv::findContours(frame, contours, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_NONE);
     
-    // Workout which countour are valid points
-    std::vector<std::vector<cv::Point> > balls;
-    std::vector<cv::Rect> ballsBox;
+    // Workout which countours are valid points
     for (size_t i = 0; i < contours.size(); i++)
     {
-        cv::drawContours(aPreview, contours, i, CV_RGB(255, 0, 0), 2);
+        if (aPreview)
+        {
+            cv::drawContours(*aPreview, contours, i, CV_RGB(255, 0, 0), 2);
+        }
+        
 
         cv::Rect bBox;
         bBox = cv::boundingRect(contours[i]);
@@ -63,15 +65,15 @@ void CvPointExtractor::extract_points(const cv::Mat& frame, cv::Mat& aPreview, s
             && bBox.area() <= maxArea
             /*&& ratio > 0.75 &&*/)
         {
-            balls.push_back(contours[i]);
-            ballsBox.push_back(bBox);
-
             vec2 center;
             center[0] = bBox.x + bBox.width / 2;
             center[1] = bBox.y + bBox.height / 2;
-            imagePoints.push_back(vec2(center));
+            aPoints.push_back(vec2(center));
 
-            cv::rectangle(aPreview, bBox, CV_RGB(0, 255, 0), 2);            
+            if (aPreview)
+            {
+                cv::rectangle(*aPreview, bBox, CV_RGB(0, 255, 0), 2);
+            }
         }
     }
 
@@ -80,23 +82,23 @@ void CvPointExtractor::extract_points(const cv::Mat& frame, cv::Mat& aPreview, s
     // Typically noise comming from zippers and metal parts on your clothing.
     // With a cap tracker it also successfully discards noise glasses.
     // However it may not work as good with a clip user wearing glasses.
-    while (imagePoints.size() > 3) // Until we have no more than three points
+    while (aPoints.size() > 3) // Until we have no more than three points
     {
         int maxY = 0;
         int index = -1;
 
         // Search for the point with highest Y coordinate
-        for (size_t i = 0; i < imagePoints.size(); i++)
+        for (size_t i = 0; i < aPoints.size(); i++)
         {
-            if (imagePoints[i][1] > maxY)
+            if (aPoints[i][1] > maxY)
             {
-                maxY = imagePoints[i][1];
+                maxY = aPoints[i][1];
                 index = i;
             }
         }
 
         // Discard it
-        imagePoints.erase(imagePoints.begin() + index);
+        aPoints.erase(aPoints.begin() + index);
     }
 
 
diff --git a/tracker-easy/cv-point-extractor.h b/tracker-easy/cv-point-extractor.h
index 65293e57..8a8ed66b 100644
--- a/tracker-easy/cv-point-extractor.h
+++ b/tracker-easy/cv-point-extractor.h
@@ -19,12 +19,12 @@
 using namespace numeric_types;
 
 
-class CvPointExtractor final : public pt_point_extractor
+class CvPointExtractor final : public IPointExtractor
 {
 public:
     // extracts points from frame and draws some processing info into frame, if draw_output is set
     // dt: time since last call in seconds
-    void extract_points(const cv::Mat& frame, cv::Mat& preview_frame, std::vector<vec2>& points, std::vector<vec2>& imagePoints) override;
+    void extract_points(const cv::Mat& frame, cv::Mat* aPreview, std::vector<vec2>& aPoints) override;
     CvPointExtractor(const QString& module_name);
 
     pt_settings s;
diff --git a/tracker-easy/frame.cpp b/tracker-easy/frame.cpp
index 90d4c6f9..12f70662 100644
--- a/tracker-easy/frame.cpp
+++ b/tracker-easy/frame.cpp
@@ -26,15 +26,6 @@ Preview& Preview::operator=(const cv::Mat& aFrame)
         return *this;
     }
 
-    const bool need_resize = iFrameRgb.cols != frame_out.cols || iFrameRgb.rows != frame_out.rows;
-    if (need_resize)
-    {
-        cv::resize(iFrameRgb, iFrameResized, cv::Size(frame_out.cols, frame_out.rows), 0, 0, cv::INTER_NEAREST);
-    }        
-    else
-    {
-        iFrameRgb.copyTo(iFrameResized);
-    }
         
     return *this;
 }
@@ -58,6 +49,17 @@ QImage Preview::get_bitmap()
         return QImage();
     }
 
+    // Resize if needed
+    const bool need_resize = iFrameRgb.cols != frame_out.cols || iFrameRgb.rows != frame_out.rows;
+    if (need_resize)
+    {
+        cv::resize(iFrameRgb, iFrameResized, cv::Size(frame_out.cols, frame_out.rows), 0, 0, cv::INTER_NEAREST);
+    }
+    else
+    {
+        iFrameRgb.copyTo(iFrameResized);
+    }
+
     cv::cvtColor(iFrameResized, frame_out, cv::COLOR_BGR2BGRA);
 
     return QImage((const unsigned char*) frame_out.data,
@@ -66,20 +68,18 @@ QImage Preview::get_bitmap()
                   QImage::Format_ARGB32);
 }
 
-void Preview::draw_head_center(Coordinates::f x, Coordinates::f y)
+void Preview::draw_head_center(numeric_types::f x, numeric_types::f y)
 {
-    auto [px_, py_] = Coordinates::to_pixel_pos(x, y, iFrameResized.cols, iFrameResized.rows);
-
-    int px = iround(px_), py = iround(py_);
+    int px = iround(x), py = iround(y);
 
     constexpr int len = 9;
 
     static const cv::Scalar color(0, 255, 255);
-    cv::line(iFrameResized,
+    cv::line(iFrameRgb,
              cv::Point(px - len, py),
              cv::Point(px + len, py),
              color, 1);
-    cv::line(iFrameResized,
+    cv::line(iFrameRgb,
              cv::Point(px, py - len),
              cv::Point(px, py + len),
              color, 1);
diff --git a/tracker-easy/frame.hpp b/tracker-easy/frame.hpp
index ba5e45e3..8493b4e9 100644
--- a/tracker-easy/frame.hpp
+++ b/tracker-easy/frame.hpp
@@ -13,7 +13,7 @@ struct Preview
 
     Preview& operator=(const cv::Mat& frame);
     QImage get_bitmap();
-    void draw_head_center(Coordinates::f x, Coordinates::f y);
+    void draw_head_center(numeric_types::f x, numeric_types::f y);
 
     operator cv::Mat&() { return iFrameResized; }
     operator cv::Mat const&() const { return iFrameResized; }
diff --git a/tracker-easy/module.cpp b/tracker-easy/module.cpp
index 86abffbc..d24a1336 100644
--- a/tracker-easy/module.cpp
+++ b/tracker-easy/module.cpp
@@ -4,7 +4,6 @@
 
 #include "module.hpp"
 #include "frame.hpp"
-#include "point_extractor.h"
 #include "cv-point-extractor.h"
 
 
@@ -18,11 +17,11 @@ static const QString module_name = "tracker-easy";
 
 namespace pt_module {
 
-struct pt_module_traits final : pt_runtime_traits
+struct pt_module_traits final : IEasyTrackerTraits
 {
-    pointer<pt_point_extractor> make_point_extractor() const override
+    pointer<IPointExtractor> make_point_extractor() const override
     {
-        return pointer<pt_point_extractor>(new CvPointExtractor(module_name));
+        return pointer<IPointExtractor>(new CvPointExtractor(module_name));
     }
 
     QString get_module_name() const override
@@ -34,7 +33,7 @@ struct pt_module_traits final : pt_runtime_traits
 
 struct tracker_pt : EasyTracker
 {
-    tracker_pt() : EasyTracker(pointer<pt_runtime_traits>(new pt_module_traits))
+    tracker_pt() : EasyTracker(pointer<IEasyTrackerTraits>(new pt_module_traits))
     {
     }
 };
diff --git a/tracker-easy/point_extractor.cpp b/tracker-easy/point_extractor.cpp
deleted file mode 100644
index 06bb6c9a..00000000
--- a/tracker-easy/point_extractor.cpp
+++ /dev/null
@@ -1,395 +0,0 @@
-/* Copyright (c) 2012 Patrick Ruoff
- * Copyright (c) 2015-2017 Stanislaw Halik <sthalik@misaki.pl>
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- */
-
-#include "point_extractor.h"
-#include "frame.hpp"
-
-#include "cv/numeric.hpp"
-#include "compat/math.hpp"
-
-#undef PREVIEW
-//#define PREVIEW
-
-#if defined PREVIEW
-#   include <opencv2/highgui.hpp>
-#endif
-
-#include <cmath>
-#include <algorithm>
-#include <cinttypes>
-#include <memory>
-
-#include <QDebug>
-
-using namespace numeric_types;
-
-// meanshift code written by Michael Welter
-
-/*
-http://en.wikipedia.org/wiki/Mean-shift
-In this application the idea, is to eliminate any bias of the point estimate 
-which is introduced by the rather arbitrary thresholded area. One must recognize
-that the thresholded area can only move in one pixel increments since it is
-binary. Thus, its center of mass might make "jumps" as pixels are added/removed
-from the thresholded area.
-With mean-shift, a moving "window" or kernel is multiplied with the gray-scale
-image, and the COM is calculated of the result. This is iterated where the
-kernel center is set the previously computed COM. Thus, peaks in the image intensity
-distribution "pull" the kernel towards themselves. Eventually it stops moving, i.e.
-then the computed COM coincides with the kernel center. We hope that the 
-corresponding location is a good candidate for the extracted point.
-The idea similar to the window scaling suggested in  Berglund et al. "Fast, bias-free 
-algorithm for tracking single particles with variable size and shape." (2008).
-*/
-static vec2 MeanShiftIteration(const cv::Mat1b &frame_gray, const vec2 &current_center, f filter_width)
-{
-    const f s = 1 / filter_width;
-
-    f m = 0;
-    vec2 com { 0, 0 };
-    for (int i = 0; i < frame_gray.rows; i++)
-    {
-        uint8_t const* const __restrict frame_ptr = frame_gray.ptr(i);
-        for (int j = 0; j < frame_gray.cols; j++)
-        {
-            f val = frame_ptr[j];
-            val = val * val; // taking the square weighs brighter parts of the image stronger.
-            f dx = (j - current_center[0])*s;
-            f dy = (i - current_center[1])*s;
-            f max = std::fmax(f(0), 1 - dx*dx - dy*dy);
-            val *= max;
-            m += val;
-            com[0] += j * val;
-            com[1] += i * val;
-        }
-    }
-    if (m > f(.1))
-    {
-        com *= 1 / m;
-        return com;
-    }
-    else
-        return current_center;
-}
-
-namespace pt_module {
-
-PointExtractor::PointExtractor(const QString& module_name) : s(module_name)
-{
-    blobs.reserve(max_blobs);
-}
-
-void PointExtractor::ensure_channel_buffers(const cv::Mat& orig_frame)
-{
-    if (ch[0].rows != orig_frame.rows || ch[0].cols != orig_frame.cols)
-        for (cv::Mat1b& x : ch)
-            x = cv::Mat1b(orig_frame.rows, orig_frame.cols);
-}
-
-void PointExtractor::ensure_buffers(const cv::Mat& frame)
-{
-    const int W = frame.cols, H = frame.rows;
-
-    if (frame_gray.rows != W || frame_gray.cols != H)
-    {
-        frame_gray = cv::Mat1b(H, W);
-        frame_bin = cv::Mat1b(H, W);
-        frame_gray_unmasked = cv::Mat1b(H, W);
-    }
-}
-
-void PointExtractor::extract_single_channel(const cv::Mat& orig_frame, int idx, cv::Mat1b& dest)
-{
-    ensure_channel_buffers(orig_frame);
-
-    const int from_to[] = {
-        idx, 0,
-    };
-
-    cv::mixChannels(&orig_frame, 1, &dest, 1, from_to, 1);
-}
-
-void PointExtractor::color_to_grayscale(const cv::Mat& frame, cv::Mat1b& output)
-{
-    switch (s.blob_color)
-    {
-    case pt_color_green_only:
-    {
-        extract_single_channel(frame, 1, output);
-        break;
-    }
-    case pt_color_blue_only:
-    {
-        extract_single_channel(frame, 0, output);
-        break;
-    }
-    case pt_color_red_only:
-    {
-        extract_single_channel(frame, 2, output);
-        break;
-    }
-    case pt_color_average:
-    {
-        const int W = frame.cols, H = frame.rows, sz = W*H;
-        cv::reduce(frame.reshape(1, sz),
-                   output.reshape(1, sz),
-                   1, cv::REDUCE_AVG);
-        break;
-    }
-    default:
-        eval_once(qDebug() << "wrong pt_color_type enum value" << int(s.blob_color));
-    [[fallthrough]];
-    case pt_color_natural:
-        cv::cvtColor(frame, output, cv::COLOR_BGR2GRAY);
-        break;
-    }
-}
-
-void PointExtractor::threshold_image(const cv::Mat& frame_gray, cv::Mat1b& output)
-{
-    const int threshold_slider_value = s.threshold_slider.to<int>();
-
-    if (!s.auto_threshold)
-    {
-        cv::threshold(frame_gray, output, threshold_slider_value, 255, cv::THRESH_BINARY);
-    }
-    else
-    {
-        const int hist_size = 256;
-        const float ranges_[] = { 0, 256 };
-        float const* ranges = (const float*) ranges_;
-
-        cv::calcHist(&frame_gray,
-                     1,
-                     nullptr,
-                     cv::noArray(),
-                     hist,
-                     1,
-                     &hist_size,
-                     &ranges);
-
-        const f radius = threshold_radius_value(frame_gray.cols, frame_gray.rows, threshold_slider_value);
-
-        float const* const __restrict ptr = hist.ptr<float>(0);
-        const unsigned area = uround(3 * pi * radius*radius);
-        const unsigned sz = unsigned(hist.cols * hist.rows);
-        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)
-                break;
-            thres = i;
-        }
-
-        cv::threshold(frame_gray, output, thres, 255, cv::THRESH_BINARY);
-    }
-}
-
-static void draw_blobs(cv::Mat& preview_frame, const blob* blobs, unsigned nblobs, const cv::Size& size)
-{
-    for (unsigned k = 0; k < nblobs; k++)
-    {
-        const blob& b = blobs[k];
-
-        if (b.radius < 0)
-            continue;
-
-        const f dpi = preview_frame.cols / f(320);
-        const f offx = 10 * dpi, offy = f(7.5) * dpi;
-
-        const f cx = preview_frame.cols / f(size.width),
-                cy = preview_frame.rows / f(size.height),
-                c  = std::fmax(f(1), cx+cy)/2;
-
-        constexpr unsigned fract_bits = 8;
-        constexpr int c_fract(1 << fract_bits);
-
-        cv::Point p(iround(b.pos[0] * cx * c_fract), iround(b.pos[1] * cy * c_fract));
-
-        auto circle_color = k >= KPointCount
-                            ? cv::Scalar(192, 192, 192)
-                            : cv::Scalar(255, 255, 0);
-
-        const int overlay_size = iround(dpi);
-
-        cv::circle(preview_frame, p, iround((b.radius + f(3.3) * c) * c_fract),
-                   circle_color, overlay_size,
-                   cv::LINE_AA, fract_bits);
-
-        char buf[16];
-        buf[sizeof(buf)-1] = '\0';
-        std::snprintf(buf, sizeof(buf) - 1, "%.2fpx", (double)b.radius);
-
-        auto text_color = k >= KPointCount
-                          ? cv::Scalar(160, 160, 160)
-                          : cv::Scalar(0, 0, 255);
-
-        cv::Point pos(iround(b.pos[0]*cx+offx), iround(b.pos[1]*cy+offy));
-        cv::putText(preview_frame, buf, pos,
-                    cv::FONT_HERSHEY_PLAIN, overlay_size, text_color,
-                    1);
-    }
-}
-
-void PointExtractor::extract_points(const cv::Mat& frame, cv::Mat& preview_frame_, std::vector<vec2>& points, std::vector<vec2>& imagePoints)
-{
-
-    ensure_buffers(frame);
-    if (frame.channels() != 1)
-    {
-        color_to_grayscale(frame, frame_gray_unmasked);
-    }
-    else
-    {
-        frame_gray_unmasked = frame;
-    }
-    
-
-#if defined PREVIEW
-    cv::imshow("capture", frame_gray);
-    cv::waitKey(1);
-#endif
-
-    threshold_image(frame_gray_unmasked, frame_bin);
-    frame_gray_unmasked.copyTo(frame_gray, frame_bin);
-
-    const f region_size_min = (f)s.min_point_size;
-    const f region_size_max = (f)s.max_point_size;
-
-    unsigned idx = 0;
-
-    blobs.clear();
-
-    for (int y=0; y < frame_bin.rows; y++)
-    {
-        const unsigned char* __restrict ptr_bin = frame_bin.ptr(y);
-        for (int x=0; x < frame_bin.cols; x++)
-        {
-            if (ptr_bin[x] != 255)
-                continue;
-            idx = blobs.size() + 1;
-
-            cv::Rect rect;
-            cv::floodFill(frame_bin,
-                          cv::Point(x,y),
-                          cv::Scalar(idx),
-                          &rect,
-                          cv::Scalar(0),
-                          cv::Scalar(0),
-                          4 | cv::FLOODFILL_FIXED_RANGE);
-
-            unsigned cnt = 0;
-            unsigned norm = 0;
-
-            const int ymax = rect.y+rect.height,
-                      xmax = rect.x+rect.width;
-
-            for (int i=rect.y; i < ymax; i++)
-            {
-                unsigned char const* const __restrict ptr_blobs = frame_bin.ptr(i);
-                unsigned char const* const __restrict ptr_gray = frame_gray.ptr(i);
-                for (int j=rect.x; j < xmax; j++)
-                {
-                    if (ptr_blobs[j] != idx)
-                        continue;
-
-                    //ptr_blobs[j] = 0;
-                    norm += ptr_gray[j];
-                    cnt++;
-                }
-            }
-
-            const f radius = std::sqrt(cnt / pi);
-            if (radius > region_size_max || radius < region_size_min)
-                continue;
-
-            blobs.emplace_back(radius,
-                               vec2(rect.width/f(2), rect.height/f(2)),
-                               std::pow(f(norm), f(1.1))/cnt,
-                               rect);
-
-            if (idx >= max_blobs)
-                goto end;
-
-            // XXX we could go to the next scanline unless the points are really small.
-            // i'd expect each point being present on at least one unique scanline
-            // but it turns out some people are using 2px points -sh 20180110
-            //break;
-        }
-    }
-end:
-
-    const int W = frame_gray.cols;
-    const int H = frame_gray.rows;
-
-    const unsigned sz = blobs.size();
-
-    std::sort(blobs.begin(), blobs.end(), [](const blob& b1, const blob& b2) { return b2.brightness < b1.brightness; });
-
-    for (idx = 0; idx < sz; ++idx)
-    {
-        blob& b = blobs[idx];
-        cv::Rect rect = b.rect;
-
-        rect.x -= rect.width / 2;
-        rect.y -= rect.height / 2;
-        rect.width *= 2;
-        rect.height *= 2;
-        rect &= cv::Rect(0, 0, W, H);  // crop at frame boundaries
-
-        cv::Mat frame_roi = frame_gray(rect);
-
-        // smaller values mean more changes. 1 makes too many changes while 1.5 makes about .1
-        static constexpr f radius_c = f(1.75);
-
-        const f kernel_radius = b.radius * radius_c;
-        vec2 pos(rect.width/f(2), rect.height/f(2)); // position relative to ROI.
-
-        for (int iter = 0; iter < 10; ++iter)
-        {
-            vec2 com_new = MeanShiftIteration(frame_roi, pos, kernel_radius);
-            vec2 delta = com_new - pos;
-            pos = com_new;
-            if (delta.dot(delta) < f(1e-3))
-                break;
-        }
-
-        b.pos[0] = pos[0] + rect.x;
-        b.pos[1] = pos[1] + rect.y;
-    }
-
-    // TODO: Do not do that if no preview. Delay blob drawing until we know where are the points?
-    draw_blobs(preview_frame_,
-               blobs.data(), blobs.size(),
-               frame_gray.size());
-
-
-    // End of mean shift code. At this point, blob positions are updated with hopefully less noisy less biased values.
-    points.reserve(max_blobs);
-    points.clear();
-
-    for (const auto& b : blobs)
-    {
-        // note: H/W is equal to fx/fy
-
-        vec2 p;
-        std::tie(p[0], p[1]) = Coordinates::to_screen_pos(b.pos[0], b.pos[1], W, H);
-        points.push_back(p);
-        imagePoints.push_back(vec2(b.pos[0], b.pos[1]));
-    }
-}
-
-blob::blob(f radius, const vec2& pos, f brightness, const cv::Rect& rect) :
-    radius(radius), brightness(brightness), pos(pos), rect(rect)
-{
-    //qDebug() << "radius" << radius << "pos" << pos[0] << pos[1];
-}
-
-} // ns pt_module
diff --git a/tracker-easy/point_extractor.h b/tracker-easy/point_extractor.h
deleted file mode 100644
index 41f74493..00000000
--- a/tracker-easy/point_extractor.h
+++ /dev/null
@@ -1,61 +0,0 @@
-/* Copyright (c) 2012 Patrick Ruoff
- * Copyright (c) 2015-2016 Stanislaw Halik <sthalik@misaki.pl>
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- */
-
-#pragma once
-
-#include "tracker-easy-api.h"
-
-#include <vector>
-
-#include <opencv2/core.hpp>
-#include <opencv2/imgproc.hpp>
-
-namespace pt_module {
-
-using namespace numeric_types;
-
-struct blob final
-{
-    f radius, brightness;
-    vec2 pos;
-    cv::Rect rect;
-
-    blob(f radius, const vec2& pos, f brightness, const cv::Rect& rect);
-};
-
-class PointExtractor final : public pt_point_extractor
-{
-public:
-    // extracts points from frame and draws some processing info into frame, if draw_output is set
-    // dt: time since last call in seconds
-    void extract_points(const cv::Mat& frame, cv::Mat& preview_frame, std::vector<vec2>& points, std::vector<vec2>& imagePoints) override;
-    PointExtractor(const QString& module_name);
-
-public:
-    std::vector<blob> blobs;
-
-private:
-    static constexpr int max_blobs = 16;
-
-    pt_settings s;
-
-    cv::Mat1b frame_gray_unmasked, frame_bin, frame_gray;
-    cv::Mat1f hist;    
-    cv::Mat1b ch[3];
-
-    void ensure_channel_buffers(const cv::Mat& orig_frame);
-    void ensure_buffers(const cv::Mat& frame);
-
-    void extract_single_channel(const cv::Mat& orig_frame, int idx, cv::Mat1b& dest);
-
-    void color_to_grayscale(const cv::Mat& frame, cv::Mat1b& output);
-    void threshold_image(const cv::Mat& frame_gray, cv::Mat1b& output);
-};
-
-} // ns impl
-
diff --git a/tracker-easy/tracker-easy-api.cpp b/tracker-easy/tracker-easy-api.cpp
index aaeb0631..2e3988a8 100644
--- a/tracker-easy/tracker-easy-api.cpp
+++ b/tracker-easy/tracker-easy-api.cpp
@@ -4,32 +4,7 @@
 using namespace numeric_types;
 
 
+IEasyTrackerTraits::IEasyTrackerTraits() = default;
+IEasyTrackerTraits::~IEasyTrackerTraits() = default;
 
-pt_runtime_traits::pt_runtime_traits() = default;
-pt_runtime_traits::~pt_runtime_traits() = default;
-pt_point_extractor::pt_point_extractor() = default;
-pt_point_extractor::~pt_point_extractor() = default;
-
-f pt_point_extractor::threshold_radius_value(int w, int h, int threshold)
-{
-    f cx = w / f{640}, cy = h / f{480};
-
-    const f min_radius = f{1.75} * cx;
-    const f max_radius = f{15} * cy;
-
-    const f radius = std::fmax(f{0}, (max_radius-min_radius) * threshold / f(255) + min_radius);
-
-    return radius;
-}
-
-std::tuple<f, f> Coordinates::to_pixel_pos(f x, f y, int w, int h)
-{
-    return std::make_tuple(w*(x+f{.5}), f{.5}*(h - 2*y*w));
-}
-
-std::tuple<f, f> Coordinates::to_screen_pos(f px, f py, int w, int h)
-{
-    px *= w/(w-f{1}); py *= h/(h-f{1});
-    return std::make_tuple((px - w/f{2})/w, -(py - h/f{2})/w);
-}
 
diff --git a/tracker-easy/tracker-easy-api.h b/tracker-easy/tracker-easy-api.h
index 40e472d4..e5627d11 100644
--- a/tracker-easy/tracker-easy-api.h
+++ b/tracker-easy/tracker-easy-api.h
@@ -22,43 +22,28 @@
 
 const int KPointCount = 3;
 
-///
-/// Utility class providing coordinates conversion functionalities
-///
-struct Coordinates final
-{
-    using f = numeric_types::f;
-
-    static std::tuple<f, f> to_pixel_pos(f x, f y, int w, int h);
-    static std::tuple<f, f> to_screen_pos(f px, f py, int w, int h);
-};
-
-
-struct pt_point_extractor
+class IPointExtractor
 {
+public:
     using vec2 = numeric_types::vec2;
     using f = numeric_types::f;
 
-    pt_point_extractor();
-    virtual ~pt_point_extractor();
-    virtual void extract_points(const cv::Mat& image, cv::Mat& preview_frame, std::vector<vec2>& points, std::vector<vec2>& imagePoints) = 0;
-
-    static f threshold_radius_value(int w, int h, int threshold);
+    virtual void extract_points(const cv::Mat& image, cv::Mat* aPreview, std::vector<vec2>& aPoints) = 0;
 };
 
-struct pt_runtime_traits
+struct IEasyTrackerTraits
 {
     template<typename t> using pointer = std::shared_ptr<t>;
 
-    pt_runtime_traits();
-    virtual ~pt_runtime_traits();
+    IEasyTrackerTraits();
+    virtual ~IEasyTrackerTraits();
 
-    virtual pointer<pt_point_extractor> make_point_extractor() const = 0;
+    virtual pointer<IPointExtractor> make_point_extractor() const = 0;
     virtual QString get_module_name() const = 0;
 };
 
 template<typename t>
-using pt_pointer = typename pt_runtime_traits::pointer<t>;
+using pt_pointer = typename IEasyTrackerTraits::pointer<t>;
 
 #ifdef __clang__
 #   pragma clang diagnostic pop
diff --git a/tracker-easy/tracker-easy-dialog.cpp b/tracker-easy/tracker-easy-dialog.cpp
index 6f7642ab..c0dd23dd 100644
--- a/tracker-easy/tracker-easy-dialog.cpp
+++ b/tracker-easy/tracker-easy-dialog.cpp
@@ -129,16 +129,8 @@ QString EasyTrackerDialog::threshold_display_text(int threshold_value)
             h = 480;
         }
 
-        //SL: sort this out 
-        /*
-        if (tracker && tracker->get_cam_info(info) && info.res_x * info.res_y != 0)
-        {
-            w = info.res_x;
-            h = info.res_y;
-        }
-        */
-
-        double value = (double)pt_point_extractor::threshold_radius_value(w, h, threshold_value);
+        //SL: What are we suppose to do here?
+        double value = 0.0f;
 
         return tr("LED radius %1 pixels").arg(value, 0, 'f', 2);
     }
diff --git a/tracker-easy/tracker-easy.cpp b/tracker-easy/tracker-easy.cpp
index 425979ef..5fd1952c 100644
--- a/tracker-easy/tracker-easy.cpp
+++ b/tracker-easy/tracker-easy.cpp
@@ -27,7 +27,7 @@
 using namespace options;
 
 
-EasyTracker::EasyTracker(pointer<pt_runtime_traits> const& traits) :
+EasyTracker::EasyTracker(pointer<IEasyTrackerTraits> const& traits) :
     traits { traits },
     s { traits->get_module_name() },
     point_extractor { traits->make_point_extractor() },
@@ -130,9 +130,9 @@ void EasyTracker::run()
                 iPreview = iMatFrame;
             }
 
-            iImagePoints.clear();
-            point_extractor->extract_points(iMatFrame, iPreview.iFrameRgb, points, iImagePoints);
-            point_count.store(points.size(), std::memory_order_relaxed);
+            iPoints.clear();
+            point_extractor->extract_points(iMatFrame, (preview_visible?&iPreview.iFrameRgb:nullptr), iPoints);
+            point_count.store(iPoints.size(), std::memory_order_relaxed);
 
             
             if (preview_visible)
@@ -146,7 +146,7 @@ void EasyTracker::run()
                 cv::destroyWindow("Preview");
             }
 
-            const bool success = points.size() >= KPointCount || iImagePoints.size() >= KPointCount;
+            const bool success = iPoints.size() >= KPointCount;
 
             int topPointIndex = -1;
 
@@ -177,9 +177,9 @@ void EasyTracker::run()
                     int minY = std::numeric_limits<int>::max();
                     for (int i = 0; i < 3; i++)
                     {
-                        if (iImagePoints[i][1]<minY)
+                        if (iPoints[i][1]<minY)
                         {
-                            minY = iImagePoints[i][1];
+                            minY = iPoints[i][1];
                             topPointIndex = i;
                         }
                     }
@@ -191,9 +191,9 @@ void EasyTracker::run()
                     for (int i = 0; i < 3; i++)
                     {
                         // Excluding top most point
-                        if (i!=topPointIndex && iImagePoints[i][0] > maxX)
+                        if (i!=topPointIndex && iPoints[i][0] > maxX)
                         {
-                            maxX = iImagePoints[i][0];
+                            maxX = iPoints[i][0];
                             rightPointIndex = i;
                         }
                     }
@@ -211,9 +211,9 @@ void EasyTracker::run()
                     }
 
                     //
-                    trackedPoints.push_back(cv::Point2f(iImagePoints[rightPointIndex][0], iImagePoints[rightPointIndex][1]));
-                    trackedPoints.push_back(cv::Point2f(iImagePoints[leftPointIndex][0], iImagePoints[leftPointIndex][1]));                    
-                    trackedPoints.push_back(cv::Point2f(iImagePoints[topPointIndex][0], iImagePoints[topPointIndex][1]));
+                    trackedPoints.push_back(cv::Point2f(iPoints[rightPointIndex][0], iPoints[rightPointIndex][1]));
+                    trackedPoints.push_back(cv::Point2f(iPoints[leftPointIndex][0], iPoints[leftPointIndex][1]));                    
+                    trackedPoints.push_back(cv::Point2f(iPoints[topPointIndex][0], iPoints[topPointIndex][1]));
 
                     std::cout << "Object: " << objectPoints << "\n";
                     std::cout << "Points: " << trackedPoints << "\n";
@@ -304,10 +304,7 @@ void EasyTracker::run()
                 if (topPointIndex != -1)
                 {
                     // Render a cross to indicate which point is the head
-                    if (points.size() >= 3)
-                    {
-                        iPreview.draw_head_center(points[topPointIndex][0], points[topPointIndex][1]);
-                    }                    
+                    iPreview.draw_head_center(iPoints[topPointIndex][0], iPoints[topPointIndex][1]);
                 }
                 
                 widget->update_image(iPreview.get_bitmap());
diff --git a/tracker-easy/tracker-easy.h b/tracker-easy/tracker-easy.h
index 6dea5712..23c9252a 100644
--- a/tracker-easy/tracker-easy.h
+++ b/tracker-easy/tracker-easy.h
@@ -36,7 +36,7 @@ struct EasyTracker : QThread, ITracker
 
     template<typename t> using pointer = pt_pointer<t>;
 
-    explicit EasyTracker(pointer<pt_runtime_traits> const& pt_runtime_traits);
+    explicit EasyTracker(pointer<IEasyTrackerTraits> const& pt_runtime_traits);
     ~EasyTracker() override;
     module_status start_tracker(QFrame* parent_window) override;
     void data(double* data) override;
@@ -50,7 +50,7 @@ private:
     bool maybe_reopen_camera();
     void set_fov(int value);
 
-    pointer<pt_runtime_traits> traits;
+    pointer<IEasyTrackerTraits> traits;
 
     QMutex camera_mtx;
 
@@ -58,12 +58,11 @@ private:
     pt_settings s;
 
     std::unique_ptr<QLayout> layout;
-    std::vector<vec2> points;
-    std::vector<vec2> iImagePoints;
+    std::vector<vec2> iPoints;
 
     int preview_width = 320, preview_height = 240;
 
-    pointer<pt_point_extractor> point_extractor;
+    pointer<IPointExtractor> point_extractor;
     std::unique_ptr<video::impl::camera> camera;
     video::impl::camera::info iCameraInfo;
     pointer<video_widget> widget;