Visual Servoing Platform  version 3.6.1 under development (2024-05-26)
tutorial-face-detector-live-threaded.cpp
#include <iostream>
#include <visp3/core/vpImageConvert.h>
#include <visp3/core/vpTime.h>
#include <visp3/detection/vpDetectorFace.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/sensor/vpV4l2Grabber.h>
#if defined(HAVE_OPENCV_OBJDETECT) && defined(HAVE_OPENCV_HIGHGUI) && defined(HAVE_OPENCV_IMGPROC) \
&& defined(HAVE_OPENCV_VIDEOIO) && defined(VISP_HAVE_THREADS)
#include <thread>
#include <mutex>
#include <opencv2/videoio.hpp>
// Shared vars
typedef enum { capture_waiting, capture_started, capture_stopped } t_CaptureState;
#if defined(VISP_HAVE_V4L2)
void captureFunction(vpV4l2Grabber &cap, std::mutex &mutex_capture, vpImage<unsigned char> &frame, t_CaptureState &capture_state)
#elif defined(HAVE_OPENCV_VIDEOIO)
void captureFunction(cv::VideoCapture &cap, std::mutex &mutex_capture, cv::Mat &frame, t_CaptureState &capture_state)
#endif
{
// If the image is larger than 640 by 480, we subsample
#if defined(VISP_HAVE_V4L2)
#elif defined(HAVE_OPENCV_VIDEOIO)
cv::Mat frame_;
#endif
bool stop_capture_ = false;
double start_time = vpTime::measureTimeSecond();
while ((vpTime::measureTimeSecond() - start_time) < 30 && !stop_capture_) {
// Capture in progress
cap >> frame_; // get a new frame from camera
// Update shared data
{
std::lock_guard<std::mutex> lock(mutex_capture);
if (capture_state == capture_stopped)
stop_capture_ = true;
else
capture_state = capture_started;
frame = frame_;
}
}
{
std::lock_guard<std::mutex> lock(mutex_capture);
capture_state = capture_stopped;
}
std::cout << "End of capture thread" << std::endl;
}
#if defined(VISP_HAVE_V4L2)
void displayFunction(std::mutex &mutex_capture, std::mutex &mutex_face, vpImage<unsigned char> &frame, t_CaptureState &capture_state, vpRect &face_bbox, bool &face_available)
#elif defined(HAVE_OPENCV_VIDEOIO)
void displayFunction(std::mutex &mutex_capture, std::mutex &mutex_face, cv::Mat &frame, t_CaptureState &capture_state, vpRect &face_bbox, bool &face_available)
#endif
{
t_CaptureState capture_state_;
bool display_initialized_ = false;
bool face_available_ = false;
vpRect face_bbox_;
#if defined(VISP_HAVE_X11)
vpDisplayX *d_ = nullptr;
#elif defined(VISP_HAVE_GDI)
vpDisplayGDI *d_ = nullptr;
#endif
do {
mutex_capture.lock();
capture_state_ = capture_state;
mutex_capture.unlock();
// Check if a frame is available
if (capture_state_ == capture_started) {
// Get the frame and convert it to a ViSP image used by the display
// class
{
std::lock_guard<std::mutex> lock(mutex_capture);
#if defined(VISP_HAVE_V4L2)
I_ = frame;
#elif defined(VISP_HAVE_OPENCV)
#endif
}
// Check if we need to initialize the display with the first frame
if (!display_initialized_) {
// Initialize the display
#if defined(VISP_HAVE_X11)
d_ = new vpDisplayX(I_);
display_initialized_ = true;
#elif defined(VISP_HAVE_GDI)
d_ = new vpDisplayGDI(I_);
display_initialized_ = true;
#endif
}
// Display the image
// Check if a face was detected
{
std::lock_guard<std::mutex> lock(mutex_face);
face_available_ = face_available;
face_bbox_ = face_bbox;
}
if (face_available_) {
// Access to the face bounding box to display it
vpDisplay::displayRectangle(I_, face_bbox_, vpColor::green, false, 4);
face_available_ = false;
}
// Trigger end of acquisition with a mouse click
vpDisplay::displayText(I_, 10, 10, "Click to exit...", vpColor::red);
if (vpDisplay::getClick(I_, false)) {
std::lock_guard<std::mutex> lock(mutex_capture);
capture_state = capture_stopped;
}
// Update the display
}
else {
vpTime::wait(2); // Sleep 2ms
}
} while (capture_state_ != capture_stopped);
#if defined(VISP_HAVE_X11) || defined(VISP_HAVE_GDI)
delete d_;
#endif
std::cout << "End of display thread" << std::endl;
}
#if defined(VISP_HAVE_V4L2)
void detectionFunction(std::mutex &mutex_capture, std::mutex &mutex_face, vpImage<unsigned char> &frame, t_CaptureState &capture_state, vpRect &face_bbox, std::string &face_cascade_name, bool &face_available)
#elif defined(HAVE_OPENCV_VIDEOIO)
void detectionFunction(std::mutex &mutex_capture, std::mutex &mutex_face, cv::Mat &frame, t_CaptureState &capture_state, vpRect &face_bbox, std::string &face_cascade_name, bool &face_available)
#endif
{
vpDetectorFace face_detector_;
face_detector_.setCascadeClassifierFile(face_cascade_name);
t_CaptureState capture_state_;
#if defined(VISP_HAVE_V4L2)
#elif defined(VISP_HAVE_OPENCV)
cv::Mat frame_;
#endif
do {
mutex_capture.lock();
capture_state_ = capture_state;
mutex_capture.unlock();
// Check if a frame is available
if (capture_state_ == capture_started) {
// Backup the frame
{
std::lock_guard<std::mutex> lock(mutex_capture);
frame_ = frame;
}
// Detect faces
bool face_found_ = face_detector_.detect(frame_);
if (face_found_) {
std::lock_guard<std::mutex> lock(mutex_face);
face_available = true;
face_bbox = face_detector_.getBBox(0); // Get largest face bounding box
}
}
else {
vpTime::wait(2); // Sleep 2ms
}
} while (capture_state_ != capture_stopped);
std::cout << "End of face detection thread" << std::endl;
}
int main(int argc, const char *argv[])
{
std::string opt_face_cascade_name = "./haarcascade_frontalface_alt.xml";
unsigned int opt_device = 0;
unsigned int opt_scale = 2; // Default value is 2 in the constructor. Turn
// it to 1 to avoid subsampling
for (int i = 0; i < argc; i++) {
if (std::string(argv[i]) == "--haar")
opt_face_cascade_name = std::string(argv[i + 1]);
else if (std::string(argv[i]) == "--device")
opt_device = (unsigned int)atoi(argv[i + 1]);
else if (std::string(argv[i]) == "--scale")
opt_scale = (unsigned int)atoi(argv[i + 1]);
else if (std::string(argv[i]) == "--help") {
std::cout << "Usage: " << argv[0]
<< " [--haar <haarcascade xml filename>] [--device <camera "
"device>] [--scale <subsampling factor>] [--help]"
<< std::endl;
return EXIT_SUCCESS;
}
}
// Instantiate the capture
#if defined(VISP_HAVE_V4L2)
std::ostringstream device;
device << "/dev/video" << opt_device;
cap.setDevice(device.str());
cap.setScale(opt_scale);
#elif defined(HAVE_OPENCV_VIDEOIO)
cv::Mat frame;
cv::VideoCapture cap;
cap.open(opt_device);
#if (VISP_HAVE_OPENCV_VERSION >= 0x030000)
int width = (int)cap.get(cv::CAP_PROP_FRAME_WIDTH);
int height = (int)cap.get(cv::CAP_PROP_FRAME_HEIGHT);
cap.set(cv::CAP_PROP_FRAME_WIDTH, width / opt_scale);
cap.set(cv::CAP_PROP_FRAME_HEIGHT, height / opt_scale);
#else
int width = cap.get(CV_CAP_PROP_FRAME_WIDTH);
int height = cap.get(CV_CAP_PROP_FRAME_HEIGHT);
cap.set(CV_CAP_PROP_FRAME_WIDTH, width / opt_scale);
cap.set(CV_CAP_PROP_FRAME_HEIGHT, height / opt_scale);
#endif
#endif
std::mutex mutex_capture;
std::mutex mutex_face;
vpRect face_bbox;
t_CaptureState capture_state = capture_waiting;
bool face_available = false;
// Start the threads
std::thread thread_capture(&captureFunction, std::ref(cap), std::ref(mutex_capture), std::ref(frame), std::ref(capture_state));
std::thread thread_display(&displayFunction, std::ref(mutex_capture), std::ref(mutex_face), std::ref(frame),
std::ref(capture_state), std::ref(face_bbox), std::ref(face_available));
std::thread thread_detection(&detectionFunction, std::ref(mutex_capture), std::ref(mutex_face), std::ref(frame),
std::ref(capture_state), std::ref(face_bbox), std::ref(opt_face_cascade_name), std::ref(face_available));
// Wait until thread ends up
thread_capture.join();
thread_display.join();
thread_detection.join();
return EXIT_SUCCESS;
}
#else
int main()
{
#ifndef VISP_HAVE_OPENCV
std::cout << "You should install OpenCV to make this example working..." << std::endl;
#elif !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
std::cout << "You should enable pthread usage and rebuild ViSP..." << std::endl;
#else
std::cout << "Multi-threading seems not supported on this platform" << std::endl;
#endif
return EXIT_SUCCESS;
}
#endif
static const vpColor red
Definition: vpColor.h:211
static const vpColor green
Definition: vpColor.h:214
vpRect getBBox(size_t i) const
void setCascadeClassifierFile(const std::string &filename)
bool detect(const vpImage< unsigned char > &I) vp_override
Display for windows using GDI (available on any windows 32 platform).
Definition: vpDisplayGDI.h:128
Use the X11 console to display images on unix-like OS. Thus to enable this class X11 should be instal...
Definition: vpDisplayX.h:128
static bool getClick(const vpImage< unsigned char > &I, bool blocking=true)
static void display(const vpImage< unsigned char > &I)
static void flush(const vpImage< unsigned char > &I)
static void displayRectangle(const vpImage< unsigned char > &I, const vpImagePoint &topLeft, unsigned int width, unsigned int height, const vpColor &color, bool fill=false, unsigned int thickness=1)
static void displayText(const vpImage< unsigned char > &I, const vpImagePoint &ip, const std::string &s, const vpColor &color)
static void convert(const vpImage< unsigned char > &src, vpImage< vpRGBa > &dest)
Defines a rectangle in the plane.
Definition: vpRect.h:76
Class that is a wrapper over the Video4Linux2 (V4L2) driver.
void open(vpImage< unsigned char > &I)
void setScale(unsigned scale=vpV4l2Grabber::DEFAULT_SCALE)
void setDevice(const std::string &devname)
VISP_EXPORT int wait(double t0, double t)
VISP_EXPORT double measureTimeSecond()