Implement Kyle Hounslow's greyscale threshold motion tracking example
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1 changed files with 74 additions and 23 deletions
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@ -12,9 +12,15 @@ using namespace std;
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class Traite_image {
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class Traite_image {
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public:
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public:
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const static int SENSITIVITY_VALUE = 30;
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const static int BLUR_SIZE = 10;
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Mat prev;
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Mat prev;
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bool first = true;
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bool first = true;
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int resize_f = 8;
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int resize_f = 1;
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int theObject[2] = {0,0};
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Rect objectBoundingRectangle = Rect(0,0,0,0);
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ros::NodeHandle n;
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ros::NodeHandle n;
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@ -47,42 +53,87 @@ class Traite_image {
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Mat next;
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Mat next;
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resize(input, next, Size(input.size().width/resize_f, input.size().height/resize_f));
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resize(input, next, Size(input.size().width/resize_f, input.size().height/resize_f));
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cvtColor(next, next, CV_BGR2GRAY);
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cvtColor(next, next, CV_BGR2GRAY);
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Mat output; // (input.rows, input.cols, CV_32FC2);
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Mat output = input.clone(); // (input.rows, input.cols, CV_32FC2);
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ROS_INFO("got input");
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//ROS_INFO("got input");
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if (first) {
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if (first) {
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prev = next.clone();
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prev = next.clone();
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first = false;
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first = false;
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ROS_INFO("first done");
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ROS_INFO("first done");
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}
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}
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//unsigned int size = input.rows * input.cols * 3;
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// Subtract the 2 last frames and threshold them
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//unsigned char* begin_input = (unsigned char*)(input.data);
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Mat thres;
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//unsigned char* end_input = (unsigned char*)(input.data) + size;
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absdiff(prev,next,thres);
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//unsigned char* out = (unsigned char*)(output.data);
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threshold(thres, thres, SENSITIVITY_VALUE, 255, THRESH_BINARY);
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//unsigned char* in = begin_input;
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// Blur to eliminate noise
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blur(thres, thres, Size(BLUR_SIZE, BLUR_SIZE));
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// This is an efficient way to process each channel in each pixel,
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threshold(thres, thres, SENSITIVITY_VALUE, 255, THRESH_BINARY);
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// with an iterator taste.
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searchForMovement(thres, output);
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//while(in != end_input) {
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// *(out++) = *(ptr_prev) - *(in);
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// *(ptr_prev++) = *(in++);
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//}
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Mat_<Point2f> flow;
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Ptr<DenseOpticalFlow> tvl1 = createOptFlow_DualTVL1();
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tvl1->calc(prev, next, flow);
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drawOpticalFlow(flow, output);
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pub.publish(cv_bridge::CvImage(msg->header, "rgb8", output).toImageMsg());
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pub.publish(cv_bridge::CvImage(msg->header, "rgb8", output).toImageMsg());
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// bridge_input is handled by a smart-pointer. No explicit delete needed.
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// bridge_input is handled by a smart-pointer. No explicit delete needed.
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ROS_INFO("pub");
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//ROS_INFO("pub");
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prev = next.clone();
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prev = next.clone();
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}
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}
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//int to string helper function
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string intToString(int number){
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//this function has a number input and string output
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std::stringstream ss;
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ss << number;
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return ss.str();
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}
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void searchForMovement(Mat thresholdImage, Mat &cameraFeed){
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//notice how we use the '&' operator for objectDetected and cameraFeed. This is because we wish
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//to take the values passed into the function and manipulate them, rather than just working with a copy.
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//eg. we draw to the cameraFeed to be displayed in the main() function.
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bool objectDetected = false;
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Mat temp;
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thresholdImage.copyTo(temp);
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//these two vectors needed for output of findContours
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vector< vector<Point> > contours;
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vector<Vec4i> hierarchy;
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//find contours of filtered image using openCV findContours function
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//findContours(temp,contours,hierarchy,CV_RETR_CCOMP,CV_CHAIN_APPROX_SIMPLE );// retrieves all contours
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findContours(temp,contours,hierarchy,CV_RETR_EXTERNAL,CV_CHAIN_APPROX_SIMPLE );// retrieves external contours
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//if contours vector is not empty, we have found some objects
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if(contours.size()>0)objectDetected=true;
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else objectDetected = false;
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if(objectDetected){
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//the largest contour is found at the end of the contours vector
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//we will simply assume that the biggest contour is the object we are looking for.
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vector< vector<Point> > largestContourVec;
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largestContourVec.push_back(contours.at(contours.size()-1));
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//make a bounding rectangle around the largest contour then find its centroid
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//this will be the object's final estimated position.
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objectBoundingRectangle = boundingRect(largestContourVec.at(0));
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int xpos = objectBoundingRectangle.x+objectBoundingRectangle.width/2;
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int ypos = objectBoundingRectangle.y+objectBoundingRectangle.height/2;
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//update the objects positions by changing the 'theObject' array values
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theObject[0] = xpos , theObject[1] = ypos;
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}
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//make some temp x and y variables so we dont have to type out so much
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int x = theObject[0];
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int y = theObject[1];
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//draw some crosshairs around the object
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circle(cameraFeed,Point(x,y),20,Scalar(0,255,0),2);
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line(cameraFeed,Point(x,y),Point(x,y-25),Scalar(0,255,0),2);
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line(cameraFeed,Point(x,y),Point(x,y+25),Scalar(0,255,0),2);
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line(cameraFeed,Point(x,y),Point(x-25,y),Scalar(0,255,0),2);
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line(cameraFeed,Point(x,y),Point(x+25,y),Scalar(0,255,0),2);
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//write the position of the object to the screen
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putText(cameraFeed,"Tracking object at (" + intToString(x)+","+intToString(y)+")",Point(x,y),1,1,Scalar(255,0,0),2);
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}
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inline bool isFlowCorrect(Point2f u)
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inline bool isFlowCorrect(Point2f u)
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{
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{
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return !cvIsNaN(u.x) && !cvIsNaN(u.y) && fabs(u.x) < 1e9 && fabs(u.y) < 1e9;
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return !cvIsNaN(u.x) && !cvIsNaN(u.y) && fabs(u.x) < 1e9 && fabs(u.y) < 1e9;
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