count the number of objects--物体计数

count the number of objects--物体计数

//Program to count the number of objects using morphology operations and the watershed transform

#include <opencv2/opencv.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>
using namespace std;
using namespace cv;
class objectCounter
{
private:
Mat image,gray,markers,output;
int count;
public:
objectCounter(Mat);   //constructor
void get_markers();//function to get markers for watershed segmentation
int count_objects();//function to implement watershed segmentation and count catchment basins
};
objectCounter::objectCounter(Mat _image)
{
image=_image.clone();
cvtColor(image,gray,CV_BGR2GRAY);
imshow("image",image);
}
void objectCounter::get_markers()
{
//equalize histogram of image to improve contrast
Mat im_e;
equalizeHist(gray,im_e);
//imshow(im_e,im_e);
//dilate to remove small black spots
Mat strel=getStructuringElement(MORPH_ELLIPSE,Size(9,9));
Mat im_d;
dilate(im_e,im_d,strel);
//imshow("im_d",im_d);
//open and close to highlight objects
strel=getStructuringElement(MORPH_ELLIPSE,Size(19,19));
Mat im_oc;
morphologyEx(im_d,im_oc,MORPH_OPEN,strel);
morphologyEx(im_oc,im_oc,MORPH_CLOSE,strel);
//imshow("im_oc",im_oc);
//adaptive threshold to create binary image
Mat th_a;
adaptiveThreshold(im_oc,th_a,255,ADAPTIVE_THRESH_MEAN_C,THRESH_BINARY,105,0);
//imshow("th_a",th_a);
//erode binary image twice to separate regions
Mat th_e;
erode(th_a,th_e,strel,Point(-1,-1),2);
//imshow("th_e",th_e);
vector<vector<Point>> c,contours;
vector<Vec4i> hierarchy;
findContours(th_e,c,hierarchy,CV_RETR_CCOMP,CV_CHAIN_APPROX_NONE);
//remove very small contours
for(int idx=0;idx>=0;idx=hierarchy[idx][0])
if(contourArea(c[idx])>20)
contours.push_back(c[idx]);
cout<<"Extracted:"<<contours.size()<<" contours"<<endl;
count=contours.size();
markers.create(image.rows,image.cols,CV_32SC1);
for(int idx=0;idx<contours.size();idx++)
drawContours(markers,contours,idx,Scalar::all(idx+1),-1,8);
}
int objectCounter::count_objects()
{
//colors generated randomly to make the output look pretty
vector<Vec3b> colorTab;
for (int i=0;i<count;i++)
{
int b=theRNG().uniform(0,255);
int g=theRNG().uniform(0,255);
int r=theRNG().uniform(0,255);
colorTab.push_back(Vec3b((uchar)b,(uchar)g,(uchar)r));
}
//watershed output image
Mat wshed(markers.size(),CV_8UC3);
//paint the watershed output image
for (int i=0;i<markers.rows;i++)
{
for (int j=0;j<markers.cols;j++)
{
int index=markers.at<int>(i,j);
if(index==-1)
wshed.at<Vec3b>(i,j)=Vec3b(255,255,255);
else if (index<=0 || index>count)
{
wshed.at<Vec3b>(i,j)=Vec3b(0,0,0);
}
else
wshed.at<Vec3b>(i,j)=colorTab[index-1];
}
}
//superimpose the watershed image with 50% transparence on the grayscale original image
Mat imgGray;
cvtColor(gray,imgGray,CV_GRAY2BGR);
wshed=wshed*0.5+imgGray*0.5;
imshow("Segmentation",wshed);
return count;
}
int main()
{
Mat im=imread("E:\\图片\\YJ.jpg");
objectCounter oc(im);
oc.get_markers();
int count=oc.count_objects();
cout<<"Counted:"<<count<<" fruits"<<endl;
while(char(waitKey(1))!='q')   { }
return 0;
}