basedline

#include <opencv\cv.h>
#include <opencv\highgui.h>
#include <iostream>
#include <string>
#include <cmath>

using namespace std;

// display video from array of frames, using left and right button.
void displayVideo(cv::Mat* frames, cv::Point2i* centralPoints, int numFrame, int FPS, string windowName) {
	double prevTick = cv::getTickCount();
	double currentTick;
	double Tickfrequency = cv::getTickFrequency();
	double waitTick = (1.0 / FPS) * Tickfrequency;
	int cntFrame = -1;
	int x, y;
	int step = frames[0].step;
	
	while (1) {
		int k = cv::waitKey(30);
		if (k != -1) cout << centralPoints[cntFrame].x << " " << centralPoints[cntFrame].y << endl;
		if (k == 2555904) { // handle right button pressed event
			cntFrame = min(cntFrame + 1, numFrame - 1);
			int xx = centralPoints[cntFrame].x;
			int yy = centralPoints[cntFrame].y;
			// display cent point (9 pixels).
			for (int i = -2; i <= 2; ++i) for (int j = -2; j <= 2; ++j) {
				x = xx + i; y = yy + j;
				frames[cntFrame].data[y * step + x] = 255;
			}
			cv::imshow(windowName, frames[cntFrame]);
		}
		if (k == 2424832) { //handle left button pressed event
			cntFrame = max(0, cntFrame - 1);
			int xx = centralPoints[cntFrame].x;
			int yy = centralPoints[cntFrame].y;
			// display cent point (9 pixels).
			for (int i = -2; i <= 2; ++i) for (int j = -2; j <= 2; ++j) {
				x = xx + i; y = yy + j;
				frames[cntFrame].data[y * step + x] = 255;
			}
			cv::imshow(windowName, frames[cntFrame]);
		}
		if (k == 27) break;
	}
}

void openVideoFromFile(string filename, int margin) {
	cv::VideoCapture cap(filename);
    if(!cap.isOpened()) {
		cout << "can't open " << filename;
        return;
	}
	
	// print video information
	int height = cap.get(CV_CAP_PROP_FRAME_HEIGHT), width = cap.get(CV_CAP_PROP_FRAME_WIDTH);
	cout << height << " x " << width << endl;
	int totalFrame = cap.get(CV_CAP_PROP_FRAME_COUNT);
	cout << totalFrame << " frames" << endl;
	int fps = cap.get(CV_CAP_PROP_FPS);
	cout << fps << " FPS" << endl;


	cv::Mat* frames = new cv::Mat[totalFrame];
	cv::Point2i* centPoints = new cv::Point2i[totalFrame];

	cv::Mat frame;
	cv::namedWindow(filename, 1);
	cv::resizeWindow(filename, width, height);

	int cntFrame = 0;
	while (cap.read(frame)) {
		cv::cvtColor(frame, frame, CV_RGB2GRAY);
		cv::Rect roi(margin, frame.rows / 4 * 3, frame.cols - margin * 2, frame.rows / 4);
		cv::Mat cropped = frame(roi); // crop 1/4 bottom of video

		cv::GaussianBlur(cropped, cropped, cv::Size(3, 11), 1);
		cv::medianBlur(cropped, cropped, 7);
		//cv::Canny(cropped, cropped, 0, 50, 3);


		// find max and min, then stretch image with log and exp
		double minVal; 
		double maxVal; 
		minMaxLoc(cropped, &minVal, &maxVal);
		cout << "min val : " << minVal << " max val: " << maxVal << endl;		
		int t;
		double lg = log(maxVal);
		for (int i = 0; i < cropped.rows; ++i) {
			for (int j = 0; j < cropped.cols; ++j) {
				t = cropped.data[i * cropped.step + j];
				cropped.data[i * cropped.step + j] = exp((double)(t - minVal) / (maxVal - minVal) * lg);
			}
		}
		

		float avg = cv::sum(cropped)[0] / (cropped.rows * cropped.cols); 
		cout << avg << endl;
		cv::Point2f leftCent(0, 0), rightCent(0, 0);
		// iterate left part and right part to find left center point & right center point
		int leftCnt = 0, rightCnt = 0;
		for (int i = 0; i < cropped.rows; ++i) {
			for (int j = 0; j < cropped.cols / 2; ++j) {
				if ((float)cropped.data[i * cropped.step + j] * 0.7  > avg) { // can change 0.7 in range (0, 1]
					cropped.data[i * cropped.step + j] = 255;
					leftCent += cv::Point2f(j, i);
					leftCnt++;
				}
			}
			for (int j = cropped.cols / 2; j < cropped.cols; ++j) {
				if ((float)cropped.data[i * cropped.step + j] * 0.7 > avg) {
					cropped.data[i * cropped.step + j] = 255;
					rightCent += cv::Point2f(j, i);
					rightCnt++;
				}
			}
		}


		cv::waitKey(1);
		imshow(filename, frame);


		// center point is middle of left center and right center
		cv::Point2f centPoint(0, 0);
		if (leftCnt != 0)
			leftCent.x /= leftCnt; leftCent.y /= leftCnt;
		if (rightCnt!= 0)
			rightCent.x /= rightCnt; rightCent.y /= rightCnt;
		frame.copyTo(frames[cntFrame]);
		centPoint = leftCent + rightCent;
		if (centPoint.x != 0) centPoint.x /= 2;
		if (centPoint.y != 0) centPoint.y /= 2;
		centPoints[cntFrame].x = (int)centPoint.x + margin;
		centPoints[cntFrame].y = (int)centPoint.y + frame.rows / 4 * 3;
		cout << centPoints[cntFrame].x << " " << centPoints[cntFrame].y << endl;
		
		cntFrame++;
	}

	cout << "Compute cent points: done!" << endl;
	displayVideo(frames, centPoints, cntFrame, 15, filename);

	delete[] frames;
	delete[] centPoints;
	cap.release();
	cv::destroyAllWindows();
}

int main() {
	string video1 = "..\\..\\Data\\01 - Nen tham, duong thang.avi";
	string video2 = "..\\..\\Data\\02 - Nen tham, duong cong.avi";
	string video3 = "..\\..\\Data\\03 - Nen da hoa, duong thang, vach ngan.avi";
	string video4 = "..\\..\\Data\\04 - Nen go, duong cong, nhieu.avi";
	string video5 = "..\\..\\Data\\05 - Nen go, nhieu lan duong (multilane).avi";
	string videos[5] = {video1, video2, video3, video4, video5};
	int margins[5] = {89, 96, 90, 96, 87};
	int video = 4;
	openVideoFromFile(videos[video - 1], margins[video - 1]);

	return 0;
}