1 files changed, 133 insertions, 0 deletions
diff --git a/eye-tracking.cpp b/eye-tracking.cpp
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+/**
+ * eye-tracking.cpp:
+ * Eye detection and tracking with OpenCV
+ *
+ * This program tries to detect and tracking the user's eye with webcam.
+ * At startup, the program performs face detection followed by eye detection 
+ * using OpenCV's built-in Haar cascade classifier. If the user's eye detected
+ * successfully, an eye template is extracted. This template will be used in 
+ * the subsequent template matching for tracking the eye.
+ */
+#include <opencv2/imgproc/imgproc.hpp>
+#include <opencv2/highgui/highgui.hpp>
+#include <opencv2/objdetect/objdetect.hpp>
+
+cv::CascadeClassifier face_cascade;
+cv::CascadeClassifier eye_cascade;
+
+/**
+ * Function to detect human face and the eyes from an image.
+ *
+ * @param  im    The source image
+ * @param  tpl   Will be filled with the eye template, if detection success.
+ * @param  rect  Will be filled with the bounding box of the eye
+ * @return zero=failed, nonzero=success
+ */
+int detectEye(cv::Mat& im, cv::Mat& tpl, cv::Rect& rect)
+{
+	std::vector<cv::Rect> faces, eyes;
+	face_cascade.detectMultiScale(im, faces, 1.1, 2, 0|CV_HAAR_SCALE_IMAGE, cv::Size(30,30));
+
+	for (int i = 0; i < faces.size(); i++)
+	{
+		cv::Mat face = im(faces[i]);
+		eye_cascade.detectMultiScale(face, eyes, 1.1, 2, 0|CV_HAAR_SCALE_IMAGE, cv::Size(20,20));
+
+		if (eyes.size())
+		{
+			rect = eyes[0] + cv::Point(faces[i].x, faces[i].y);
+			tpl  = im(rect);
+		}
+	}
+
+	return eyes.size();
+}
+
+/**
+ * Perform template matching to search the user's eye in the given image.
+ *
+ * @param   im    The source image
+ * @param   tpl   The eye template
+ * @param   rect  The eye bounding box, will be updated with the new location of the eye
+ */
+void trackEye(cv::Mat& im, cv::Mat& tpl, cv::Rect& rect)
+{
+	cv::Size size(rect.width * 2, rect.height * 2);
+	cv::Rect window(rect + size - cv::Point(size.width/2, size.height/2));
+	
+	window &= cv::Rect(0, 0, im.cols, im.rows);
+
+	cv::Mat dst(window.width - tpl.rows + 1, window.height - tpl.cols + 1, CV_32FC1);
+	cv::matchTemplate(im(window), tpl, dst, CV_TM_SQDIFF_NORMED);
+
+	double minval, maxval;
+	cv::Point minloc, maxloc;
+	cv::minMaxLoc(dst, &minval, &maxval, &minloc, &maxloc);
+
+	if (minval <= 0.2)
+	{
+		rect.x = window.x + minloc.x;
+		rect.y = window.y + minloc.y;
+	}
+	else
+		rect.x = rect.y = rect.width = rect.height = 0;
+}
+
+int main(int argc, char** argv)
+{
+	// Load the cascade classifiers
+	// Make sure you point the XML files to the right path, or 
+	// just copy the files from [OPENCV_DIR]/data/haarcascades directory
+	face_cascade.load("haarcascade_frontalface_alt2.xml");
+	eye_cascade.load("haarcascade_eye.xml");
+
+	// Open webcam
+	cv::VideoCapture cap(0);
+
+	// Check if everything is ok
+	if (face_cascade.empty() || eye_cascade.empty() || !cap.isOpened())
+		return 1;
+
+	// Set video to 320x240
+	cap.set(CV_CAP_PROP_FRAME_WIDTH, 320);
+	cap.set(CV_CAP_PROP_FRAME_HEIGHT, 240);
+
+	cv::Mat frame, eye_tpl;
+	cv::Rect eye_bb;
+
+	while (cv::waitKey(15) != 'q')
+	{
+		cap >> frame;
+		if (frame.empty())
+			break;
+
+		// Flip the frame horizontally, Windows users might need this
+		cv::flip(frame, frame, 1);
+
+		// Convert to grayscale and 
+		// adjust the image contrast using histogram equalization
+		cv::Mat gray;
+		cv::cvtColor(frame, gray, CV_BGR2GRAY);
+
+		if (eye_bb.width == 0 && eye_bb.height == 0)
+		{
+			// Detection stage
+			// Try to detect the face and the eye of the user
+			detectEye(gray, eye_tpl, eye_bb);
+		}
+		else
+		{
+			// Tracking stage with template matching
+			trackEye(gray, eye_tpl, eye_bb);
+
+			// Draw bounding rectangle for the eye
+			cv::rectangle(frame, eye_bb, CV_RGB(0,255,0));
+		}
+
+		// Display video
+		cv::imshow("video", frame);
+	}
+
+	return 0;
+}
+