main.cpp

/*****************************************************************************
*   Markerless AR desktop application.
******************************************************************************
*   by Khvedchenia Ievgen, 5th Dec 2012
*   http://computer-vision-talks.com
******************************************************************************
*   Ch3 of the book "Mastering OpenCV with Practical Computer Vision Projects"
*   Copyright Packt Publishing 2012.
*   http://www.packtpub.com/cool-projects-with-opencv/book
*****************************************************************************/

////////////////////////////////////////////////////////////////////
// File includes:
#include "ARDrawingContext.hpp"
#include "ARPipeline.hpp"
#include "DebugHelpers.hpp"

////////////////////////////////////////////////////////////////////
// Standard includes:
#include <opencv2/opencv.hpp>
#include <gl/gl.h>
#include <gl/glu.h>

/**
 * Processes a recorded video or live view from web-camera and allows you to adjust homography refinement and 
 * reprojection threshold in runtime.
 */
void processVideo(const cv::Mat& patternImage, CameraCalibration& calibration, cv::VideoCapture& capture);

/**
 * Processes single image. The processing goes in a loop.
 * It allows you to control the detection process by adjusting homography refinement switch and 
 * reprojection threshold in runtime.
 */
void processSingleImage(const cv::Mat& patternImage, CameraCalibration& calibration, const cv::Mat& image);

/**
 * Performs full detection routine on camera frame and draws the scene using drawing context.
 * In addition, this function draw overlay with debug information on top of the AR window.
 * Returns true if processing loop should be stopped; otherwise - false.
 */
bool processFrame(const cv::Mat& cameraFrame, ARPipeline& pipeline, ARDrawingContext& drawingCtx);

int main(int argc, const char * argv[])
{
    // Change this calibration to yours:
    CameraCalibration calibration(526.58037684199849f, 524.65577209994706f, 318.41744018680112f, 202.96659047014398f);
    
    if (argc < 2)
    {
        std::cout << "Input image not specified" << std::endl;
        std::cout << "Usage: markerless_ar_demo <pattern image> [filepath to recorded video or image]" << std::endl;
        return 1;
    }

    // Try to read the pattern:
    cv::Mat patternImage = cv::imread(argv[1]);
    if (patternImage.empty())
    {
        std::cout << "Input image cannot be read" << std::endl;
        return 2;
    }

    if (argc == 2)
    {
        processVideo(patternImage, calibration, cv::VideoCapture());
    }
    else if (argc == 3)
    {
        std::string input = argv[2];
        cv::Mat testImage = cv::imread(input);
        if (!testImage.empty())
        {
            processSingleImage(patternImage, calibration, testImage);
        }
        else 
        {
            cv::VideoCapture cap;
            if (cap.open(input))
            {
                processVideo(patternImage, calibration, cap);
            }
        }
    }
    else
    {
        std::cerr << "Invalid number of arguments passed" << std::endl;
        return 1;
    }

    return 0;
}

void processVideo(const cv::Mat& patternImage, CameraCalibration& calibration, cv::VideoCapture& capture)
{
    // Grab first frame to get the frame dimensions
    cv::Mat currentFrame;  
    capture >> currentFrame;

    // Check the capture succeeded:
    if (currentFrame.empty())
    {
        std::cout << "Cannot open video capture device" << std::endl;
        return;
    }

    cv::Size frameSize(currentFrame.cols, currentFrame.rows);

    ARPipeline pipeline(patternImage, calibration);
    ARDrawingContext drawingCtx("Markerless AR", frameSize, calibration);

    bool shouldQuit = false;
    do
    {
        capture >> currentFrame;
        if (currentFrame.empty())
        {
            shouldQuit = true;
            continue;
        }

        shouldQuit = processFrame(currentFrame, pipeline, drawingCtx);
    } while (!shouldQuit);
}

void processSingleImage(const cv::Mat& patternImage, CameraCalibration& calibration, const cv::Mat& image)
{
    cv::Size frameSize(image.cols, image.rows);
    ARPipeline pipeline(patternImage, calibration);
    ARDrawingContext drawingCtx("Markerless AR", frameSize, calibration);

    bool shouldQuit = false;
    do
    {
        shouldQuit = processFrame(image, pipeline, drawingCtx);
    } while (!shouldQuit);
}

bool processFrame(const cv::Mat& cameraFrame, ARPipeline& pipeline, ARDrawingContext& drawingCtx)
{
    // Clone image used for background (we will draw overlay on it)
    cv::Mat img = cameraFrame.clone();

    // Draw information:
    if (pipeline.m_patternDetector.enableHomographyRefinement)
        cv::putText(img, "Pose refinement: On   ('h' to switch off)", cv::Point(10,15), CV_FONT_HERSHEY_PLAIN, 1, CV_RGB(0,200,0));
    else
        cv::putText(img, "Pose refinement: Off  ('h' to switch on)",  cv::Point(10,15), CV_FONT_HERSHEY_PLAIN, 1, CV_RGB(0,200,0));

    cv::putText(img, "RANSAC threshold: " + ToString(pipeline.m_patternDetector.homographyReprojectionThreshold) + "( Use'-'/'+' to adjust)", cv::Point(10, 30), CV_FONT_HERSHEY_PLAIN, 1, CV_RGB(0,200,0));

    // Set a new camera frame:
    drawingCtx.updateBackground(img);

    // Find a pattern and update it's detection status:
    drawingCtx.isPatternPresent = pipeline.processFrame(cameraFrame);

    // Update a pattern pose:
    drawingCtx.patternPose = pipeline.getPatternLocation();

    // Request redraw of the window:
    drawingCtx.updateWindow();

    // Read the keyboard input:
    int keyCode = cv::waitKey(5); 

    bool shouldQuit = false;
    if (keyCode == '+' || keyCode == '=')
    {
        pipeline.m_patternDetector.homographyReprojectionThreshold += 0.2f;
        pipeline.m_patternDetector.homographyReprojectionThreshold = std::min(10.0f, pipeline.m_patternDetector.homographyReprojectionThreshold);
    }
    else if (keyCode == '-')
    {
        pipeline.m_patternDetector.homographyReprojectionThreshold -= 0.2f;
        pipeline.m_patternDetector.homographyReprojectionThreshold = std::max(0.0f, pipeline.m_patternDetector.homographyReprojectionThreshold);
    }
    else if (keyCode == 'h')
    {
        pipeline.m_patternDetector.enableHomographyRefinement = !pipeline.m_patternDetector.enableHomographyRefinement;
    }
    else if (keyCode == 27 || keyCode == 'q')
    {
        shouldQuit = true;
    }

    return shouldQuit;
}