example_reconstructmesdk_calibration.cpp

Content

This example shows how to calibrate a sensor.

Boost is only used to generate examples and is not necessary for working with this SDK.

#include <boost/test/unit_test.hpp>

#include <reconstructmesdk/reme.h>
#include <stdio.h>
#include <conio.h>

BOOST_AUTO_TEST_SUITE(example_reconstructmesdk)

BOOST_AUTO_TEST_CASE(calibration)
{
  puts("Key mapping");
  puts("s: capture image of calibration target");
  puts("c: perform calibration and exit");
  puts("All keys need to be pressed with the command line in the foreground");

  // Create a new context
  reme_context_t c;
  reme_context_create(&c);

  // Create a license object
  reme_license_t l;
  reme_license_create(c, &l);
  reme_license_authenticate(c, l, "license.txt.sgn");

  // Create a new sensor with default intrinsics
  reme_sensor_t s;
  reme_sensor_create(c, "mskinect", false, &s);

  // We by either enabling IR stream or RGB (default) for REME_IMAGE_AUX we
  // can choose the camera to calibrate.

  reme_options_t o_cfg;
  reme_options_create(c, &o_cfg);
  reme_sensor_bind_camera_options(c, s, o_cfg);

  // Switch IR stream on.
  reme_options_set(c, o_cfg, "enable_rgb", "false");
  reme_options_set(c, o_cfg, "enable_ir", "true");
  reme_options_set(c, o_cfg, "enable_ir_projector", "false");
  // Increase contrast of the image. We've found that good values are 
  //  - Kinect for Windows: around 40 with projector turned off
  //  - Kinect for XBox, Xtion: around 4 with projector covered
  reme_options_set(c, o_cfg, "ir_alpha", "40");

  reme_sensor_open(c, s);

  // Create a calibrator using standard settings (A3 chessboard 10x7)
  reme_calibrator_t calib;
  reme_calibrator_create(c, &calib);
  
  // We visualize two images, the auxilary image and the last detection result
  reme_viewer_t viewer;
  reme_viewer_create_image(c, "This is ReconstructMeSDK", &viewer);

  reme_image_t imgs[2];
  reme_image_create(c, &imgs[0]);
  reme_image_create(c, &imgs[1]);

  reme_viewer_add_image(c, viewer, imgs[0]);
  reme_viewer_add_image(c, viewer, imgs[1]);

  bool continue_grabbing = true;

  while (continue_grabbing && REME_SUCCESS(reme_sensor_grab(c, s))) 
  {
    // Prepare image and update content
    reme_sensor_prepare_image(c, s, REME_IMAGE_AUX);
    reme_sensor_update_image(c, s, REME_IMAGE_AUX, imgs[0]);

    // Keyboard handling
    if (_kbhit()) { 
      char k = _getch();
      switch(k) {

        // Key 's' tries to find the calibration target in the current image
        case 's': 
          {
            reme_calibrator_add_image(c, calib, imgs[0]);
            reme_calibrator_update_detection_image(c, calib, imgs[1]);
            break;
          }

        // Key 'c' saves the volume content to disk
        case 'c' : 
          {
            continue_grabbing = false;            
            break;
          }

      }
    }

    // Update the viewer
    reme_viewer_update(c, viewer);

  } // end of grabbing loop

  // Actual calibration step

  float accuracy;
  if (REME_SUCCESS(reme_calibrator_calibrate(c, calib, &accuracy))) {
    printf("Reprojection error: %f pixels \n", accuracy);

    // Generate a new sensor config using the new intrinsic values
    reme_options_t o, o_intr, o_intr_new;
    
    reme_options_create(c, &o);
    reme_options_create(c, &o_intr);
    reme_options_create(c, &o_intr_new);

    // Get the current camera configuration
    reme_sensor_bind_camera_options(c, s, o);
    reme_options_bind_message(c, o, "depth_intrinsics", o_intr);

    // Get the result of the calibration
    reme_calibrator_bind_intrinsics(c, calib, o_intr_new);
    
    // Copy over
    reme_options_copy(c, o_intr_new, o_intr);

    // Reset the flags we pulled in before
    reme_options_set(c, o_cfg, "enable_rgb", "true");
    reme_options_set(c, o_cfg, "enable_ir", "false");
    reme_options_set(c, o_cfg, "enable_ir_projector", "true");

    // Save new config to file
    reme_options_save_to_file(c, o, "calibrated_sensor.txt");
  } else{
    puts("Calibration failed");
  }

  // Make sure to release all memory acquired
  reme_context_destroy(&c);

}

BOOST_AUTO_TEST_SUITE_END()