我有这个编码相关的问题找到轮廓 [英] I Have prob with this coding related to find the contours

问题描述

我想找到每个轮廓的质心，因为我采取一些示例代码和测试它有一个prob这个coding.i有一个错误...请帮助我解决这个...对我来说非常有用...感谢提前...我使用windows平台与visual studio 2008

I want to find the centroid of each contour.for that i take some sample code and test it..i have a prob with this coding.i got an error...Please help me to resolve that...this very useful for me...Thanks in advance...I use windows platform with visual studio 2008

#include <cv.h>
#include <highgui.h>
#include <iostream>
#include <stdio.h>
#include <stdlib.h>

using namespace cv;
using namespace std;

Mat src; 
Mat src_gray;
int thresh = 100;
int max_thresh = 255;
RNG rng(12345);

/// Function header
void thresh_callback(int, void* );

/** @function main */
int main( int argc, char** argv )
{
  /// Load source image and convert it to gray
  IplImage* src = cvLoadImage( "TEST2.jpg");

  /// Convert image to gray and blur it
  cvtColor( src, src_gray, CV_BGR2GRAY );
  blur( src_gray, src_gray, Size(3,3) );

  /// Create Window
  char* source_window = "Source";
  namedWindow( source_window, CV_WINDOW_AUTOSIZE );
  imshow( source_window, src );

  createTrackbar( "Canny thresh:","Source", &thresh, max_thresh, thresh_callback );
  thresh_callback(0,0);

  waitKey(0);
  return(0);
}

/** @function thresh_callback */
void thresh_callback(int, void* )
{
  Mat canny_output;
  vector<vector<Point>> contours;
  vector<Vec4i> hierarchy;

  /// Detect edges using canny
  Canny( src_gray, canny_output, thresh,thresh*2,3);
  /// Find contours
  findContours( canny_output, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) );

  /// Get the moments
  vector<Moments> mu(contours.size());
  for( int i = 0; i < contours.size(); i++ )
  { 
    mu[i] = moments( contours[i], false ); 
  }

  ///  Get the mass centers:
  vector<Point2f> mc( contours.size() );
  for( int i = 0; i < contours.size(); i++ )
  {
    mc[i] = Point2f( mu[i].m10/mu[i].m00 , mu[i].m01/mu[i].m00 ); 
  }

  /// Draw contours
  Mat drawing = Mat::zeros( canny_output.size(), CV_8UC3 );
  for( int i = 0; i< contours.size(); i++ )
     {
       Scalar color = Scalar( rng.uniform(0, 255), rng.uniform(0,255), rng.uniform(0,255) );
       drawContours( drawing, contours, i, color, 2, 8, hierarchy, 0, Point() );
       circle( drawing, mc[i], 4, color, -1, 8, 0 );
     }

  /// Show in a window
  namedWindow( "Contours", CV_WINDOW_AUTOSIZE );
  imshow( "Contours", drawing );

  /// Calculate the area with the moments 00 and compare with the result of the OpenCV function
  printf("\t Info: Area and Contour Length \n");
  for( int i = 0; i< contours.size(); i++ )
     {
       printf(" * Contour[%d] - Area (M_00) = %.2f - Area OpenCV: %.2f - Length: %.2f \n", i, mu[i].m00, contourArea(contours[i]), arcLength( contours[i], true ) );
       Scalar color = Scalar( rng.uniform(0, 255), rng.uniform(0,255), rng.uniform(0,255) );
       drawContours( drawing, contours, i, color, 2, 8, hierarchy, 0, Point() );
       circle( drawing, mc[i], 4, color, -1, 8, 0 );
     }



}

错误喜欢...

 Error  2   error C2664: 'cv::moments' : cannot convert parameter 1 from 'std::vector<_Ty>' to 'const cv::Mat &'    d:\aranga_try\new_opencv\new_opencv\auto_focustest.cpp  57  New_opencv
    Error   8   error C2664: 'cv::contourArea' : cannot convert parameter 1 from 'std::vector<_Ty>' to 'const cv::Mat &'    d:\aranga_try\new_opencv\new_opencv\auto_focustest.cpp  84  New_opencv
    Error   9   error C2664: 'cv::arcLength' : cannot convert parameter 1 from 'std::vector<_Ty>' to 'const cv::Mat &'  d:\aranga_try\new_opencv\new_opencv\auto_focustest.cpp  84  New_opencv

推荐答案

您需要显式转换 std :: vector< cv :: Point> 到 cv :: Mat ，通过调用

You need to explicitly convert std::vector<cv::Point> to cv::Mat by calling

template<typename _Tp> explicit Mat(const vector<_Tp>& vec, bool copyData=false);

获得矩阵后，可以计算矩，面积或周长。例如，要计算面积：

After getting the matrix, you can compute moments, area or perimeter. For example, to compute area:

double area = cv::contourArea(cv::Mat(contours[i], false));

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