opencv_contrib/modules/line_descriptor/samples/knn_matching.cpp

/*M///////////////////////////////////////////////////////////////////////////////////////
 //
 //  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
 //
 //  By downloading, copying, installing or using the software you agree to this license.
 //  If you do not agree to this license, do not download, install,
 //  copy or use the software.
 //
 //
 //                           License Agreement
 //                For Open Source Computer Vision Library
 //
 // Copyright (C) 2014, Biagio Montesano, all rights reserved.
 // Third party copyrights are property of their respective owners.
 //
 // Redistribution and use in source and binary forms, with or without modification,
 // are permitted provided that the following conditions are met:
 //
 //   * Redistribution's of source code must retain the above copyright notice,
 //     this list of conditions and the following disclaimer.
 //
 //   * Redistribution's in binary form must reproduce the above copyright notice,
 //     this list of conditions and the following disclaimer in the documentation
 //     and/or other materials provided with the distribution.
 //
 //   * The name of the copyright holders may not be used to endorse or promote products
 //     derived from this software without specific prior written permission.
 //
 // This software is provided by the copyright holders and contributors "as is" and
 // any express or implied warranties, including, but not limited to, the implied
 // warranties of merchantability and fitness for a particular purpose are disclaimed.
 // In no event shall the Intel Corporation or contributors be liable for any direct,
 // indirect, incidental, special, exemplary, or consequential damages
 // (including, but not limited to, procurement of substitute goods or services;
 // loss of use, data, or profits; or business interruption) however caused
 // and on any theory of liability, whether in contract, strict liability,
 // or tort (including negligence or otherwise) arising in any way out of
 // the use of this software, even if advised of the possibility of such damage.
 //
 //M*/

#include <opencv2/line_descriptor.hpp>

#include "opencv2/core/utility.hpp"
#include "opencv2/core/private.hpp"
#include <opencv2/imgproc.hpp>
#include <opencv2/features2d.hpp>
#include <opencv2/highgui.hpp>

#include <iostream>
#include <vector>
#include <time.h>

using namespace cv;
using namespace cv::line_descriptor;

static const char* keys =
{ "{@image_path1 | | Image path 1 }"
    "{@image_path2 | | Image path 2 }" };

static void help()
{
  std::cout << "\nThis example shows the functionalities of descriptors matching\n" << "Please, run this sample using a command in the form\n"
            << "./example_line_descriptor_matching <path_to_input_image 1>" << "<path_to_input_image 2>" << std::endl;

}

uchar invertSingleBits( uchar dividend_char, int numBits );

/* invert numBits bits in input char */
uchar invertSingleBits( uchar dividend_char, int numBits )
{
  std::vector<int> bin_vector;
  long dividend;
  long bin_num;

  /* convert input char to a long */
  dividend = (long) dividend_char;

  /*if a 0 has been obtained, just generate a 8-bit long vector of zeros */
  if( dividend == 0 )
    bin_vector = std::vector<int>( 8, 0 );

  /* else, apply classic decimal to binary conversion */
  else
  {
    while ( dividend >= 1 )
    {
      bin_num = dividend % 2;
      dividend /= 2;
      bin_vector.push_back( bin_num );
    }
  }

  /* ensure that binary vector always has length 8 */
  if( bin_vector.size() < 8 )
  {
    std::vector<int> zeros( 8 - bin_vector.size(), 0 );
    bin_vector.insert( bin_vector.end(), zeros.begin(), zeros.end() );
  }

  /* invert numBits bits */
  for ( int index = 0; index < numBits; index++ )
  {
    if( bin_vector[index] == 0 )
      bin_vector[index] = 1;

    else
      bin_vector[index] = 0;
  }

  /* reconvert to decimal */
  uchar result = 0;
  for ( int i = (int) bin_vector.size() - 1; i >= 0; i-- )
    result += (uchar) ( bin_vector[i] * pow( 2, i ) );

  return result;
}

int main( int argc, char** argv )
{
  /* get parameters from comand line */
  CommandLineParser parser( argc, argv, keys );
  String image_path1 = parser.get<String>( 0 );
  String image_path2 = parser.get<String>( 1 );

  if( image_path1.empty() || image_path2.empty() )
  {
    help();
    return -1;
  }

  /* load image */
  cv::Mat imageMat1 = imread( image_path1, 1 );
  cv::Mat imageMat2 = imread( image_path2, 1 );

  if( imageMat1.data == NULL || imageMat2.data == NULL )
  {
    std::cout << "Error, images could not be loaded. Please, check their paths" << std::endl;
  }

  /* create binary masks */
  cv::Mat mask1 = Mat::ones( imageMat1.size(), CV_8UC1 );
  cv::Mat mask2 = Mat::ones( imageMat2.size(), CV_8UC1 );

  /* create a pointer to a BinaryDescriptor object with default parameters */
  Ptr<BinaryDescriptor> bd = BinaryDescriptor::createBinaryDescriptor();

  /* compute lines */
  std::vector<KeyLine> keylines1, keylines2;
  bd->detect( imageMat1, keylines1, mask1 );
  bd->detect( imageMat2, keylines2, mask2 );

  /* compute descriptors */
  cv::Mat descr1, descr2;
  bd->compute( imageMat1, keylines1, descr1 );
  bd->compute( imageMat2, keylines2, descr2 );

  /* create a BinaryDescriptorMatcher object */
  Ptr<BinaryDescriptorMatcher> bdm = BinaryDescriptorMatcher::createBinaryDescriptorMatcher();

  /* make a copy of descr2 mat */
  Mat descr2Copy = descr1.clone();

  /* randomly change some bits in original descriptors */
  srand( (unsigned int) time( NULL ) );

  for ( int j = 0; j < descr1.rows; j++ )
  {
    /* select a random column */
    int randCol = rand() % 32;

    /* get correspondent data */
    uchar u = descr1.at<uchar>( j, randCol );

    /* change bits */
    for ( int k = 1; k <= 5; k++ )
    {
      /* copy current row to train matrix */
      descr2Copy.push_back( descr1.row( j ) );

      /* invert k bits */
      uchar uc = invertSingleBits( u, k );

      /* update current row in train matrix */
      descr2Copy.at<uchar>( descr2Copy.rows - 1, randCol ) = uc;
    }
  }

  /* prepare a structure to host matches */
  std::vector<std::vector<DMatch> > matches;

  /* require knn match */
  bdm->knnMatch( descr1, descr2, matches, 6 );

}