Configured the red ball detection color parameters.

data/color_params.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0"?>
+<opencv_storage>
+<lowH>0</lowH>
+<highH>179</highH>
+<lowS>105</lowS>
+<highS>255</highS>
+<lowV>210</lowV>
+<highV>255</highV>
+</opencv_storage>

makefile

@@ -1,5 +1,6 @@
-all:  ReadWrite MonoCamCalib 
+all:  ReadWrite MonoCamCalib RedBallDetection
 	g++ lib/MonoCameraCalibration.o lib/ReadWriteFunctions.o -o bin/MonoCameraCalibration -L/usr/lib/x86_64-linux-gnu `pkg-config --libs opencv4`
+	g++ lib/RedBallDetection.o -o bin/RedBallDetection -L/usr/lib/x86_64-linux-gnu `pkg-config --libs opencv4`
 	
 MonoCamCalib: src/MonoCameraCalibration.cpp
 	g++ -c src/MonoCameraCalibration.cpp -o lib/MonoCameraCalibration.o -I./include -I/usr/include/opencv4
@@ -7,6 +8,9 @@ MonoCamCalib: src/MonoCameraCalibration.cpp
 ReadWrite: src/ReadWriteFunctions.cpp
 	g++ -c src/ReadWriteFunctions.cpp -o lib/ReadWriteFunctions.o -I./include -I/usr/include/opencv4
 	
+RedBallDetection: src/RedBallDetection.cpp
+	g++ -c src/RedBallDetection.cpp -o lib/RedBallDetection.o -I./include -I/usr/include/opencv4
+
 
 clean:
 	rm lib/*.o

src/RedBallDetection.cpp

@@ -0,0 +1,208 @@
+#include <iostream>
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+
+#include <opencv2/highgui.hpp>
+#include <opencv2/imgproc.hpp>
+#include <opencv2/calib3d.hpp>
+
+#define CAM_PARAMS_FILENAME "./data/camera_calibration_params.xml"
+#define COLOR_PARAMS_FILENAME "./data/color_params.xml"
+#define FPS 30.0
+#define STRUCTURAL_ELEMENTS_SIZE 5
+#define RESOLUTION_MAX 800
+
+bool readCameraParameters(std::string filename, cv::Mat &camMatrix, cv::Mat & distCoeffs)
+{
+	cv::FileStorage fs(filename, cv::FileStorage::READ);
+	if (!fs.isOpened())
+	{
+		std::cout << "[ERROR] Could not open the camera parameter file storage: " <<  filename << " !"<< std::endl;
+		return false;
+	}
+	
+	fs["camera_matrix"] >> camMatrix;
+	fs["distortion_coefficients"] >> distCoeffs;
+	
+	return true;
+}
+
+bool writeColorParameters(std::string filename, int iLowH, int iHighH, int iLowS, int iHighS, int iLowV, int iHighV)
+{
+	cv::FileStorage fs(filename, cv::FileStorage::WRITE);
+	if (!fs.isOpened())
+	{
+		std::cout << "[ERROR] Could not open the file storage: " <<  filename << " !"<< std::endl;
+		return false;
+	}
+	fs << "lowH" << iLowH;
+	fs << "highH" << iHighH;
+	
+	fs << "lowS" << iLowS;
+	fs << "highS" << iHighS;
+	
+	fs << "lowV" << iLowV;
+	fs << "highV" << iHighV;
+	
+	// releases the writer
+        fs.release();
+
+	return true;
+}
+
+int main(int argc, char** argv)
+{	
+	// initializes main parameters
+	std::string sCameraParamFilename = CAM_PARAMS_FILENAME;
+	std::string sColorParamFilename = COLOR_PARAMS_FILENAME;
+	int iStructuralElementSize = STRUCTURAL_ELEMENTS_SIZE;
+	float fFPS = FPS;
+	int iMaxVideoResolution = RESOLUTION_MAX;
+	
+	// updates main parameters from arguments
+	int opt;
+	while ((opt = getopt (argc, argv, ":i:f:o:s:r:")) != -1)
+	{
+		switch (opt)
+		{
+			case 'o':
+				sColorParamFilename = optarg;
+				break;
+			case 'f':
+				fFPS = atof(optarg); 
+				break;
+			case 'i':
+				sCameraParamFilename = optarg;
+				break;
+			case 's':
+				iStructuralElementSize = atoi(optarg);
+				break;
+			case 'r':
+				iMaxVideoResolution = atoi(optarg);
+				break;
+			case '?':
+				if (optopt == 'o' || optopt == 'f' || optopt == 'i' || optopt == 's' || optopt == 'r')
+					fprintf (stderr, "Option -%c requires an argument.\n", optopt);
+				else if (isprint (optopt))
+					fprintf (stderr, "Unknown option `-%c'.\n", optopt);
+				else
+					fprintf (stderr, "Unknown option character `\\x%x'.\n", optopt);
+				return 1;
+			default:
+				abort ();
+		}
+	}
+	
+	// distorted/undistorted image
+	bool bIsImageUndistorted = true;
+	
+	// reads camera intrinsic parameters
+	cv::Mat cameraMatrix, distCoeffs;
+	bool isCamParamsSet = readCameraParameters(sCameraParamFilename, cameraMatrix, distCoeffs);
+	
+	// checks if the camera parameters were successfully read
+	if (!isCamParamsSet)
+	{
+		std::cout << "[WARNING] Camera intrinsic parameters could not be loaded!" << std::endl;
+	}
+	
+	// creates a camera grabber
+	cv::VideoCapture cap(0, cv::CAP_V4L2);
+	
+	// changes image resolution to maximum (e.g. 1920x1080 if possible)
+	cap.set(cv::CAP_PROP_FRAME_HEIGHT, iMaxVideoResolution); cap.set(cv::CAP_PROP_FRAME_WIDTH, iMaxVideoResolution);
+	
+	// checks if the camera was successfully opened
+	if (!cap.isOpened())
+	{
+		std::cout << "[ERROR] Cannot open the webcam" << std::endl;
+		return 1;
+	}
+	
+	cv::namedWindow("Control", cv::WINDOW_AUTOSIZE); //create a window called "Control"
+
+	// sets min/max value for HSV color representation
+	int iLowH = 0;
+	int iHighH = 179;
+
+	int iLowS = 0; 
+	int iHighS = 255;
+
+	int iLowV = 0;
+	int iHighV = 255;
+
+	// creates trackbars in "Control" window
+	cv::createTrackbar("LowH", "Control", &iLowH, 179); //Hue (0 - 179)
+	cv::createTrackbar("HighH", "Control", &iHighH, 179);
+
+	cv::createTrackbar("LowS", "Control", &iLowS, 255); //Saturation (0 - 255)
+	cv::createTrackbar("HighS", "Control", &iHighS, 255);
+
+	cv::createTrackbar("LowV", "Control", &iLowV, 255); //Value (0 - 255)
+	cv::createTrackbar("HighV", "Control", &iHighV, 255);
+
+	while (true)
+	{
+		cv::Mat imgOriginal;
+
+		bool bSuccess = cap.read(imgOriginal); // read a new frame from video
+
+		if (!bSuccess) //if not success, break loop
+		{
+			std::cout << "[WARNING] Cannot read a frame from video stream" << std::endl;
+			break;
+		}
+		
+		if (bIsImageUndistorted && isCamParamsSet)
+		{
+			cv::Mat temp = imgOriginal.clone();
+			cv::undistort(temp, imgOriginal, cameraMatrix, distCoeffs);
+		}
+		
+		//Convert the captured frame from BGR to HSV
+		cv::Mat imgHSV;
+		cvtColor(imgOriginal, imgHSV, cv::COLOR_BGR2HSV); 
+
+		//Threshold the image based on the trackbar values
+		cv::Mat imgThresholded;
+		inRange(imgHSV, cv::Scalar(iLowH, iLowS, iLowV), cv::Scalar(iHighH, iHighS, iHighV), imgThresholded); 
+
+		//morphological opening (remove small objects from the foreground)
+		cv::erode(imgThresholded, imgThresholded, cv::getStructuringElement(cv::MORPH_ELLIPSE, cv::Size(iStructuralElementSize, iStructuralElementSize)) );
+		cv::dilate( imgThresholded, imgThresholded, cv::getStructuringElement(cv::MORPH_ELLIPSE, cv::Size(iStructuralElementSize, iStructuralElementSize)) ); 
+
+		//morphological closing (fill small holes in the foreground)
+		cv::dilate( imgThresholded, imgThresholded, cv::getStructuringElement(cv::MORPH_ELLIPSE, cv::Size(iStructuralElementSize, iStructuralElementSize)) ); 
+		cv::erode(imgThresholded, imgThresholded, cv::getStructuringElement(cv::MORPH_ELLIPSE, cv::Size(iStructuralElementSize, iStructuralElementSize)) );
+
+		cv::imshow("Thresholded Image", imgThresholded); //show the thresholded image
+		cv::imshow("Original", imgOriginal); //show the original image
+
+		// waits for awhile depending on the FPS value
+		// checks if ESC was pressed to exit
+		char key = (char)cv::waitKey(1000.0/fFPS);
+		//wait for 'esc' key press for 30ms. If 'esc' key is pressed, break loop
+		if (key == 27)
+		{
+			std::cout << "[INFO] esc key is pressed by user -> Shuting down!" << std::endl;
+			break; 
+		}
+		if (key == 'u')
+		{
+			bIsImageUndistorted = !bIsImageUndistorted;
+			std::cout << "[INFO] Image undistorted: " <<  bIsImageUndistorted<< std::endl;
+		}
+		if (key == 's')
+		{
+			writeColorParameters(sColorParamFilename, iLowH, iHighH, iLowS, iHighS, iLowV, iHighV);
+			std::cout << "[INFO] Color parameters saved to file: " <<  sColorParamFilename << std::endl;
+		}
+		
+		
+	}
+
+	return 0;
+}