1 files changed, 151 insertions, 0 deletions
diff --git a/tracker-easy/point-extractor.cpp b/tracker-easy/point-extractor.cpp
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+/* 
+ * Copyright (c) 2019 Stephane Lenclud
+ *
+ * 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 "preview.h"
+#include "tracker-easy.h"
+
+#include "cv/numeric.hpp"
+#include "compat/math.hpp"
+#include <opencv2/imgproc/types_c.h>
+
+#include <cmath>
+#include <algorithm>
+#include <cinttypes>
+#include <memory>
+
+#include <QDebug>
+
+using namespace numeric_types;
+
+namespace EasyTracker
+{
+
+    PointExtractor::PointExtractor() : s(KModuleName)
+    {
+    
+    }
+
+
+    void PointExtractor::extract_points(const cv::Mat& aFrame, cv::Mat* aPreview, std::vector<vec2>& aPoints)
+    {
+        //TODO: Assert if channel size is neither one nor two
+        // Make sure our frame channel is 8 bit
+        size_t channelSize = aFrame.elemSize1();
+        if (channelSize == 2)
+        {
+            // We have a 16 bits single channel. Typically coming from Kinect V2 IR sensor
+            // Resample to 8-bits
+            double min = std::numeric_limits<uint16_t>::min();
+            double max = std::numeric_limits<uint16_t>::max();
+            //cv::minMaxLoc(raw, &min, &max); // Should we use 16bit min and max instead?
+            // For scalling to have more precission in the range we are interrested in
+            min = max - 255;
+            // See: https://stackoverflow.com/questions/14539498/change-type-of-mat-object-from-cv-32f-to-cv-8u/14539652
+            aFrame.convertTo(iFrameChannelSizeOne, CV_8U, 255.0 / (max - min), -255.0*min / (max - min));
+        }
+        else
+        {
+            iFrameChannelSizeOne = aFrame;
+        }
+
+
+        // Make sure our frame has a single channel
+        // Make an extra copy if needed
+        const int channelCount = iFrameChannelSizeOne.channels();
+        if (channelCount == 3)
+        {
+            // Convert to grayscale
+            // TODO: What's our input format, BRG or RGB?
+            // That won't make our point extraction work but at least it won't crash
+            cv::cvtColor(iFrameChannelSizeOne, iFrameGray, cv::COLOR_BGR2GRAY);
+            // TODO: Instead convert to HSV and use a key color together with cv::inRange to sport the color we want.
+            // Key color should be defined in settings.
+        }
+        else if (channelCount == 1)
+        {
+            // No further convertion needed
+            iFrameGray = iFrameChannelSizeOne;
+        }
+        else
+        {
+            eval_once(qDebug() << "tracker/easy: camera frame depth not supported" << aFrame.channels());
+            return;
+        }
+
+        // Contours detection
+        std::vector<std::vector<cv::Point> > contours;
+        cv::findContours(iFrameGray, contours, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_NONE);
+    
+        // Workout which countours are valid points
+        for (size_t i = 0; i < contours.size(); i++)
+        {
+            if (aPreview)
+            {
+                cv::drawContours(*aPreview, contours, (int)i, CV_RGB(255, 0, 0), 2);
+            }
+        
+
+            cv::Rect bBox;
+            bBox = cv::boundingRect(contours[i]);
+
+            float ratio = (float)bBox.width / (float)bBox.height;
+            if (ratio > 1.0f)
+                ratio = 1.0f / ratio;
+
+       
+            // Searching for a bBox almost square
+            float minArea = s.min_point_size*s.min_point_size;
+            float maxArea = s.max_point_size*s.max_point_size;
+            if (bBox.width >= s.min_point_size
+                && bBox.height >= s.min_point_size
+                && bBox.width <= s.max_point_size
+                && bBox.height <= s.max_point_size
+                && bBox.area() >= minArea
+                && bBox.area() <= maxArea
+                /*&& ratio > 0.75 &&*/)
+            {
+                vec2 center;
+                center[0] = bBox.x + bBox.width / 2;
+                center[1] = bBox.y + bBox.height / 2;
+                aPoints.push_back(vec2(center));
+
+                if (aPreview)
+                {
+                    cv::rectangle(*aPreview, bBox, CV_RGB(0, 255, 0), 2);
+                }
+            }
+        }
+
+        // Keep only the three points which are highest, i.e. with lowest Y coordinates
+        // That's most usefull to discard noise from features below your cap/head.
+        // Typically noise comming from zippers and metal parts on your clothing.
+        // With a cap tracker it also successfully discards noise from glasses.
+        // However it may not work as good with a clip user wearing glasses.
+        while (aPoints.size() > 3) // Until we have no more than three points
+        {
+            int maxY = 0;
+            size_t index = -1;
+
+            // Search for the point with highest Y coordinate
+            for (size_t i = 0; i < aPoints.size(); i++)
+            {
+                if (aPoints[i][1] > maxY)
+                {
+                    maxY = aPoints[i][1];
+                    index = i;
+                }
+            }
+
+            // Discard it
+            aPoints.erase(aPoints.begin() + index);
+        }
+    }
+
+}
+