ExampleLEDDetector.cpp

Example for LED spot detector in images.

Author

esquivel 11/2013

/*
  This file is part of the BIAS library (Basic ImageAlgorithmS).

  Copyright (C) 2003-2009    (see file CONTACT for details)
  Multimediale Systeme der Informationsverarbeitung
  Institut fuer Informatik
  Christian-Albrechts-Universitaet Kiel


  BIAS is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  BIAS is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with BIAS; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <bias_config.h>
#ifndef BIAS_HAVE_OPENCV
#  error Please recompile BIAS with USE_OPENCV to use this code. 
#endif
#include <Base/Common/W32Compat.hh>
#include <Base/Image/Image.hh>
#include <Base/Image/ImageConvert.hh>
#include <Base/Image/ImageIO.hh>
#include <Base/ImageUtils/ImageDraw.hh>
#include <Base/Math/Vector2.hh>
#include <Base/Math/Vector3.hh>
#include <FeatureDetector/LEDDetector.hh>
#include <iostream>
#include <string>
#include <vector>

using namespace std;
using namespace BIAS;

/**
  @example ExampleLEDDetector.cpp
  @brief   Example for LED spot detector in images.
  @relates LEDDetector
  @ingroup g_examples
  @author  esquivel 11/2013
*/
int main(int argc, char** argv)
{
  if (argc < 2) {
    cout << "Usage : ExampleLEDDetector <image> [-c <num>]" << endl
         << " -c <num> :  Work on channel <num> of color image" << endl;
    return 0;
  }

  // load image
  BIAS::Image<unsigned char> image;
  if (BIAS::ImageIO::Load(argv[1], image) != 0) {
    cout << "Error : Failed to load image " << argv[1] << "!" << endl;
    return -1;
  }

  // extract red channel
  if (argc > 2 && strcmp(argv[2], "-c") == 0) {
    int channel = argc > 3 ? atoi(argv[3]) : 0;
    int channels = image.GetChannelCount();
    if (channel < 0 || channel >= channels) {
      cout << "Invalid channel " << channel << " given, ignoring option -c" << endl;
    } else if (channels > 1) {
      cout << "Working on channel " << channel << " of color image" << endl;
      BIAS::ImageConvert::GetChannel<unsigned char>(image, channel);
    }
  }

  // detect LED spots
  BIAS::LEDDetector detector;
  std::vector<BIAS::Vector3<double> > pos;
  detector.Compute(image, pos);

  // compute radius of LED spots
  std::vector<double> r(pos.size());
  {
    std::vector<double> minx, maxx, maxval;
    detector.GetAttributes(minx, maxx, maxval);
    BIASASSERT(minx.size() == pos.size() && maxx.size() == pos.size());
    for (unsigned int i = 0; i < pos.size(); i++)
      r[i] = 0.5 * (maxx[i] - minx[i]);
  }

  // find closest LED spot to image center
  unsigned int i_center = 0;
  double d_center = 1e8;
  BIAS::Vector2<double> c(image.GetWidth() / 2, image.GetHeight() / 2);
  for (unsigned int i = 0; i < pos.size(); i++) {
    double d = BIAS::Vector2<double>(pos[i][0] - c[0], pos[i][1] - c[1]).NormL2();
    if (d < d_center) {
      i_center = i;
      d_center = d;
    }
  }

  // draw detected LED spots into image
  unsigned char col[3] = { 0, 0, 0 };
  cout << "Detected " << pos.size() << " LED spots : " << endl;
  for (unsigned int i = 0; i < pos.size(); i++) {
    cout << (i == i_center ? "X " : "  ") << pos[i] << endl << flush;
    if (i == i_center) col[0] = 255; else col[0] = 0;
    BIAS::ImageDraw<unsigned char>::
      CircleCenterFilled(image, (int)(pos[i][0]+0.5), (int)(pos[i][1]+0.5), 2, col);
    BIAS::ImageDraw<unsigned char>::
      CircleCenter(image, (int)(pos[i][0]+0.5), (int)(pos[i][1]+0.5), (int)(r[i]+0.5), col);
  }

  // save output image
  const std::string filename = "ExampleLEDDetector.png";
  if (BIAS::ImageIO::Save(filename, image) == 0) {
    cout << "Saved output image to " << filename << endl;
  } else {
    cout << "Error : Failed to write image to " << filename << "!" << endl;
    return -1;
  }
  return 0;
}