images.cpp

This example can be found in Development\images\images.cpp.

This example shows how to enable image transfer on the PST Tracker and how to use the PST SDK to retrieve images. Images are 8 bit grayscale and are stored as an unsigned char* without memory alignment or padding.

#ifdef WIN32
#include <windows.h>
#endif

/*
* Define handler functions required to ensure a clean shutdown of the PST Tracker when the
* application is terminated.
*/

static void Exithandler(int sig);

#ifdef WIN32
BOOL WINAPI ConsoleHandler(DWORD CEvent)
{
    Exithandler(CEvent);
    return TRUE;
}
#endif

/* End of handler functions */

#include <memory>
#include <iostream>

#include "pst-sdk.h"
#include "TrackerExceptions.h"

/* Control variable for main loop */
static bool running = true;

/* Number of data points to grab before application termination */
static const uint32_t numberOfSamplesToGrab = 1000;

/*
* Implementation of the PSTech::pstsdk::Listener class to receive tracking data.
* The OnTrackerData() callback function receives the data as soon as it becomes
* available.
*/
class MyListener : public PSTech::pstsdk::Listener
{
    virtual void OnTrackerData(PSTech::pstsdk::TrackerData& td)
    {
        static uint32_t samplesGrabbed = 0;
        if (samplesGrabbed++ >= numberOfSamplesToGrab)
            running = false;

        // Do something with the received data.
    }
} listener;

/*
* Create a shared pointer for storing the PSTech::pstsdk::Tracker object instance.
* By making use of a shared pointer, proper destruction of the PST Tracker connection
* is ensured in case the application is shut down.
*/
std::shared_ptr<PSTech::pstsdk::Tracker> pst;

/*
* Implement the exit handler to shut-down the PST Tracker connection on application terrmination.
*/
static void Exithandler(int sig)
{
    pst->Shutdown();
}

int main(int argc, char *argv[])
{
    // Register the exit handler with the application
#ifdef WIN32
    SetConsoleCtrlHandler((PHANDLER_ROUTINE)ConsoleHandler, TRUE);
#else
    signal(SIGTERM, Exithandler);
    signal(SIGKILL, Exithandler);
    signal(SIGQUIT, Exithandler);
    signal(SIGINT, Exithandler);
#endif

    // Implement error handling of PSTech::TrackerException exceptions to prevent 
    // improper PST Tracker shutdown on errors.
    try
    {
        // Create an instance of the Tracker object using the default configuration path and file names.
        pst = std::make_shared<PSTech::pstsdk::Tracker>();

        // Print version number of the tracker server being used.
        std::cout << "Running PST Server version " << pst->GetVersionInfo() << "\n";

        // Register the listener object to the tracker server.
        pst->AddTrackerListener(&listener);

        // Start the tracker server.
        pst->Start();

        // Perform a system check to see if the tracker server is running OK and print the result.
        std::cout << "System check: " << (int)pst->Systemcheck() << "\n\n";
        std::cout << "***************************\n\n";

        // Set the frame rate to 60 Hz.
        pst->SetFramerate(60);
        std::cout << "Current frame rate: " << pst->GetFramerate() << " Hz\n\n";

        // In order to start receiving images, enable image transfer. When image transfer is disabled, 
        // the vector of images returned by GetImage will be empty.
        pst->EnableImageTransfer();

        // The standard PST trackers will run at a reduced frame rate of 30 Hz when image transfer is enabled.
        // However, since this frame rate is temporary for as long as image transfer is enabled, that frame rate
        // will not be reported as the current frame rate.
        std::cout << "Enabled image transfer. Current frame rate: " << pst->GetFramerate() << " Hz\n\n";
        std::cout << "***************************\n\n";

        // Try to capture 100 images.
        for (int i = 0; i < 100; ++i)
        {
            // Get a reference to the last grabbed image in the PSTech::pstsdk::Image struct.
            // Note that enabling image transfer takes some time. While image transfer is being enabled,
            // the images vector in the PSTech::pstsdk::Image struct will be empty.
            PSTech::pstsdk::Image images;
            bool succes = pst->GetImage(images);
            std::cout << "Retrieval operation " << ((succes) ? "successful!\n" : "unsuccesful!\n\n");
            if (succes)
            {
                std::cout << "Retrieved " << images.images.size() << " image(s) of size: " << images.width << " X " << images.height << "\n\n";
                // Do something with the image.
            }
        }

        // Wait for 5 seconds, since this is > 4 seconds, image transfer will be disabled automatically.
        Sleep(5000);

        // Try to grab one image. Since image retrieval timed out, it should return an empty image vector.
        PSTech::pstsdk::Image images;
        bool succes = pst->GetImage(images);
        std::cout << "Retrieval operation " << ((succes) ? "successful!\n" : "unsuccesful!");
        if (succes)
        {
            std::cout << "Retrieved " << images.images.size() << " image(s) of size: " << images.width << " X " << images.height << "\n\n";
        }

        // Main loop, wait for auto-termination.
        while (running)
        {
            Sleep(100);
        }
    }
    catch (PSTech::TrackerException &e)
    {
        // Catch PSTech::TrackerException exceptions and print error messages.
        std::cout << e.full_description() << "\n";
    }

    // Make sure that the connection to the PST Tracker is shut down properly.
    pst->Shutdown();

    // Pause command line to see results.
    std::cout << "Press enter to continue...\n";
    std::cin.get();

    return 0;
}