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| -rw-r--r-- | eye-tracking.cpp | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/eye-tracking.cpp b/eye-tracking.cpp new file mode 100644 index 0000000..ae5cdfd --- /dev/null +++ b/eye-tracking.cpp @@ -0,0 +1,133 @@ +/** + * 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; +} + |