lsd线特征提取和bd匹配

Question

在运行线特征匹配的demo时发现，lsd算法时倾向于用octave == 1，对图像也要resize，如果想得到原图像上的匹配结果，改这俩地方还是会出错，错误大概是数组出界，这是什么原因呢

#include <opencv2/line_descriptor.hpp>

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

#include <iostream>

#define MATCHES_DIST_THRESHOLD 25

using namespace cv;
using namespace cv::line_descriptor;

static const char* keys =
    {
      "{ 1 | | | path to image1 }"
      "{ 2 | | | path to image2 }"
    };

static void help()
{
  std::cout << "\nThis example shows the functionalities of lines extraction "
            << "and descriptors computation furnished by BinaryDescriptor class\n"
            << "Please, run this sample using a command in the form\n"
            << "./example_line_descriptor_compute_descriptors <path_to_input_image 1> "
            << "<path_to_input_image 2>" << std::endl;
}

int main( int argc, const char** argv )
{
  /* get parameters from command line */
  CommandLineParser parser( argc, argv, keys );
  String image_path1 = parser.get<String>( "1" );
  String image_path2 = parser.get<String>( "2" );

  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 path" << 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 and descriptors */
  std::vector<KeyLine> keylines1, keylines2;
  cv::Mat descr1, descr2;

  ( *bd )( imageMat1, mask1, keylines1, descr1, false, false );
  ( *bd )( imageMat2, mask2, keylines2, descr2, false, false );

  /* select keylines from first octave and their descriptors */
  std::vector<KeyLine> lbd_octave1, lbd_octave2;
  Mat left_lbd, right_lbd;
  for ( int i = 0; i < (int) keylines1.size(); i++ )
  {
    if( keylines1[i].octave == 0 )
    {
      lbd_octave1.push_back( keylines1[i] );
      left_lbd.push_back( descr1.row( i ) );
    }
  }

  for ( int j = 0; j < (int) keylines2.size(); j++ )
  {
    if( keylines2[j].octave == 0 )
    {
      lbd_octave2.push_back( keylines2[j] );
      right_lbd.push_back( descr2.row( j ) );
    }
  }

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

  /* require match */
  std::vector<DMatch> matches;
  bdm->match( left_lbd, right_lbd, matches );

  /* select best matches */
  std::vector<DMatch> good_matches;
  for ( int i = 0; i < (int) matches.size(); i++ )
  {
    if( matches[i].distance < MATCHES_DIST_THRESHOLD )
      good_matches.push_back( matches[i] );
  }

  /* plot matches */
  cv::Mat outImg;
  cv::Mat scaled1, scaled2;
  std::vector<char> mask( matches.size(), 1 );
  drawLineMatches( imageMat1, lbd_octave1, imageMat2, lbd_octave2, good_matches, outImg, Scalar::all( -1 ), Scalar::all( -1 ), mask,
                     DrawLinesMatchesFlags::DEFAULT );

  imshow( "Matches", outImg );
  waitKey();
  imwrite("/home/ubisum/Desktop/images/env_match/matches.jpg", outImg);
  /* create an LSD detector */
  Ptr<LSDDetector> lsd = LSDDetector::createLSDDetector();

  /* detect lines */
  std::vector<KeyLine> klsd1, klsd2;
  Mat lsd_descr1, lsd_descr2;
  lsd->detect( imageMat1, klsd1, 2, 2, mask1 );
  lsd->detect( imageMat2, klsd2, 2, 2, mask2 );

  /* compute descriptors for lines from first octave */
  bd->compute( imageMat1, klsd1, lsd_descr1 );
  bd->compute( imageMat2, klsd2, lsd_descr2 );

  /* select lines and descriptors from first octave */
  std::vector<KeyLine> octave0_1, octave0_2;
  Mat leftDEscr, rightDescr;
  for ( int i = 0; i < (int) klsd1.size(); i++ )
  {
    if( klsd1[i].octave == 1 )
    {
      octave0_1.push_back( klsd1[i] );
      leftDEscr.push_back( lsd_descr1.row( i ) );
    }
  }

  for ( int j = 0; j < (int) klsd2.size(); j++ )
  {
    if( klsd2[j].octave == 1 )
    {
      octave0_2.push_back( klsd2[j] );
      rightDescr.push_back( lsd_descr2.row( j ) );
    }
  }

  /* compute matches */
  std::vector<DMatch> lsd_matches;
  bdm->match( leftDEscr, rightDescr, lsd_matches );

  /* select best matches */
  good_matches.clear();
  for ( int i = 0; i < (int) lsd_matches.size(); i++ )
  {
    if( lsd_matches[i].distance < MATCHES_DIST_THRESHOLD )
      good_matches.push_back( lsd_matches[i] );
  }

  /* plot matches */
  cv::Mat lsd_outImg;
  resize( imageMat1, imageMat1, Size( imageMat1.cols / 2, imageMat1.rows / 2 ) );
  resize( imageMat2, imageMat2, Size( imageMat2.cols / 2, imageMat2.rows / 2 ) );
  std::vector<char> lsd_mask( matches.size(), 1 );
  drawLineMatches( imageMat1, octave0_1, imageMat2, octave0_2, good_matches, lsd_outImg, Scalar::all( -1 ), Scalar::all( -1 ), lsd_mask,
                   DrawLinesMatchesFlags::DEFAULT );

  imshow( "LSD matches", lsd_outImg );
  waitKey();


}

Answer 1

不知道你这个问题是否已经解决, 如果还没有解决的话:

• 请看👉 ：LSD 直线检测

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