Hu距完整代码（OpenCV-Python）

计算Hu距：

C++

#include "opencv2/opencv.hpp"

using namespace cv;
using namespace std;

int main(int argc, char **argv)
{
  bool showLogTransformedHuMoments = true; 

  for (int i = 1; i < argc; i++)
  {
    // Obtain filename from command line argument
    string filename(argv[i]); 

    // Read Image
    Mat im = imread(filename,IMREAD_GRAYSCALE); 
    
    // Threshold image
    threshold(im, im, 128, 255, THRESH_BINARY);
  
    // Calculate Moments
    Moments moment = moments(im, false);

    // Calculate Hu Moments
    double huMoments[7];
    HuMoments(moment, huMoments);

    // Print Hu Moments
    cout << filename << ": "; 
    
    for(int i = 0; i < 7; i++)
    {
      if(showLogTransformedHuMoments)
      {
        // Log transform Hu Moments to make squash the range
        cout << -1 * copysign(1.0, huMoments[i]) * log10(abs(huMoments[i])) << " ";  
      }
      else 
      {
        // Hu Moments without log transform. 
        cout << huMoments[i] << " ";  
      }
      
    }
    // One row per file
    cout << endl; 

  }
  


}

Python

import cv2, sys, os
from math import copysign, log10

def main():
    showLogTransformedHuMoments = True

    for i in range(1,len(sys.argv)):

        # Obtain filename from command line argument
        filename = sys.argv[i]

        # Read image
        im = cv2.imread(filename,cv2.IMREAD_GRAYSCALE)

        # Threshold image
        _,im = cv2.threshold(im, 128, 255, cv2.THRESH_BINARY)

        # Calculate Moments
        moment = cv2.moments(im)

        # Calculate Hu Moments
        huMoments = cv2.HuMoments(moment)

        # Print Hu Moments
        print("{}: ".format(filename),end='')

        for i in range(0,7):
            if showLogTransformedHuMoments:
                # Log transform Hu Moments to make
                # squash the range
                print("{:.5f}".format(-1*copysign(1.0,\
                        huMoments[i])*log10(abs(huMoments[i]))),\
                        end=' ')
            else:
                # Hu Moments without log transform
                print("{:.5f}".format(huMoments[i]),end=' ')
        print()

if __name__ == "__main__":
    main()

匹配Hu距

C++

#include "opencv2/opencv.hpp"

using namespace cv;
using namespace std;

int main(int argc, char **argv)
{
  Mat im1 = imread("images/S0.png",IMREAD_GRAYSCALE);
  Mat im2 = imread("images/K0.png",IMREAD_GRAYSCALE);
  Mat im3 = imread("images/S4.png",IMREAD_GRAYSCALE);

  double m1 = matchShapes(im1, im1, CONTOURS_MATCH_I2, 0);
  double m2 = matchShapes(im1, im2, CONTOURS_MATCH_I2, 0);
  double m3 = matchShapes(im1, im3, CONTOURS_MATCH_I2, 0);

  cout << "Shape Distances Between " << endl << "-------------------------" << endl;
  cout << "S0.png and S0.png : " << m1 << endl;
  cout << "S0.png and K0.png : " << m2 << endl;
  cout << "S0.png and S4.png : " << m3 << endl;
}

Python

import cv2

def main():

    im1 = cv2.imread("images/S0.png",cv2.IMREAD_GRAYSCALE)
    im2 = cv2.imread("images/K0.png",cv2.IMREAD_GRAYSCALE)
    im3 = cv2.imread("images/S4.png",cv2.IMREAD_GRAYSCALE)

    m1 = cv2.matchShapes(im1,im1,cv2.CONTOURS_MATCH_I2,0)
    m2 = cv2.matchShapes(im1,im2,cv2.CONTOURS_MATCH_I2,0)
    m3 = cv2.matchShapes(im1,im3,cv2.CONTOURS_MATCH_I2,0)

    print("Shape Distances Between \n-------------------------")

    print("S0.png and S0.png : {}".format(m1))
    print("S0.png and K0.png : {}".format(m2))
    print("S0.png and S4.png : {}".format(m3))

if __name__ == "__main__":
    main()