Matcher functionalities' tests completed

modules/line_descriptor/samples/knn_matching.cpp

@@ -0,0 +1,169 @@
+#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>
+
+using namespace cv;
+
+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;
+
+}
+
+/* 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;
+    for(int i = (int)bin_vector.size()-1; i>=0; i--)
+        result += 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 (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);
+
+    /* visualize matches and Hamming distances */
+    for(size_t v = 0; v<matches.size(); v++)
+    {
+        for(size_t m = 0; m<matches[v].size(); m++)
+        {
+            DMatch dm = matches[v][m];
+            std::cout << dm.queryIdx << " " << dm.trainIdx << " "
+                      << dm.distance << std::endl;
+        }
+    }
+
+}
+
+