Example: vision_multiple_checkerboards

C++ example source code:

/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2023, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

#include <mrpt/gui/CDisplayWindow.h>
#include <mrpt/system/CTimeLogger.h>
#include <mrpt/vision/chessboard_camera_calib.h>
#include <mrpt/vision/chessboard_find_corners.h>

#include <iostream>

using namespace std;
using namespace mrpt;
using namespace mrpt::img;
using namespace mrpt::vision;
using namespace mrpt::system;
using namespace mrpt::gui;

#include <mrpt/examples_config.h>
std::string myDataDir =
    MRPT_EXAMPLES_BASE_DIRECTORY + string("vision_multiple_checkerboards/");

// ------------------------------------------------------
//              TestMultipleCheckerboard
// ------------------------------------------------------
void TestMultipleCheckerboard(
    const std::string& img_filename, const unsigned int checkerboard_size_x,
    const unsigned int checkerboard_size_y)
{
    CTimeLogger timlog;

    // Load img:
    CImage img;
    if (!img.loadFromFile(img_filename))
        throw std::runtime_error("Can't load image!");

    // Detect multiple-checkerboards:
    vector<vector<TPixelCoordf>> listCornerCoords;

    timlog.enter("findMultipleChessboardsCorners");

    mrpt::vision::findMultipleChessboardsCorners(
        img, listCornerCoords, checkerboard_size_x, checkerboard_size_y);

    timlog.leave("findMultipleChessboardsCorners");

    cout << "Number of checkerboards detected: " << listCornerCoords.size()
         << endl;

    // Draw:
    CImage img_detect;
    img.colorImage(img_detect);
    for (size_t i = 0; i < listCornerCoords.size(); i++)
        img_detect.drawChessboardCorners(
            listCornerCoords[i], checkerboard_size_x, checkerboard_size_y);

    // Show results:
    CDisplayWindow win1("Detected checkerboards ");
    win1.showImage(img_detect);

    timlog.dumpAllStats();
    timlog.clear();

    // wait till user closes any window:
    win1.waitForKey();
}

// ------------------------------------------------------
//                      MAIN
// ------------------------------------------------------
int main(int argc, char** argv)
{
    try
    {
        std::string sFile = myDataDir + string("test_3_checkerboards_5x4.jpg");
        unsigned int checkerboard_size_x = 5;
        unsigned int checkerboard_size_y = 4;

        if (argc == 4)
        {
            sFile = std::string(argv[1]);
            checkerboard_size_x = atoi(argv[2]);
            checkerboard_size_y = atoi(argv[3]);
        }
        else if (argc != 1)
        {
            std::cerr << "Usage: " << argv[0] << " [IMAGE_FILE NX NY]\n";
            return 1;
        }

        TestMultipleCheckerboard(
            sFile, checkerboard_size_x, checkerboard_size_y);
        return 0;
    }
    catch (const std::exception& e)
    {
        std::cerr << "MRPT error: " << mrpt::exception_to_str(e) << std::endl;
        return -1;
    }
}