案例二 图像分割

基于连通域的图像分割案例

可以用于物体计数和区域分割
码上 后期进行更改优化

#include 
#include "opencv2/imgproc.hpp"
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
#include 
 
using namespace cv;
using namespace std;
 
Mat img;
int threshval = 100;
 
static void on_trackbar(int, void*)
{
    Mat bw = threshval < 128 ? (img < threshval) : (img > threshval);
    Mat labelImage(img.size(), CV_32S);
    int nLabels = connectedComponents(bw, labelImage, 8);
    std::vector colors(nLabels);
    colors[0] = Vec3b(0, 0, 0);//background
    for (int label = 1; label < nLabels; ++label) {
        colors[label] = Vec3b((rand() & 255), (rand() & 255), (rand() & 255));
    }
    Mat dst(img.size(), CV_8UC3);
    for (int r = 0; r < dst.rows; ++r) {
        for (int c = 0; c < dst.cols; ++c) {
            int label = labelImage.at(r, c);
            Vec3b &pixel = dst.at(r, c);
            pixel = colors[label];
        }
    }
 
    imshow("Connected Components", dst);
}
 
static void help()
{
    cout << "\n This program demonstrates connected components and use of the trackbar\n"
        "Usage: \n"
        "  ./connected_components \n"
        "The image is converted to grayscale and displayed, another image has a trackbar\n"
        "that controls thresholding and thereby the extracted contours which are drawn in color\n";
}
 
const char* keys =
{
    "{help h||}{@image|../data/stuff.jpg|image for converting to a grayscale}"
};
 
int main(int argc, const char** argv)
{
    CommandLineParser parser(argc, argv, keys);
    if (parser.has("help"))
    {
        help();
        return 0;
    }
    string inputImage = parser.get(0);
    //img = imread(inputImage.c_str(), 0);
    img = imread("1.png", 0);
    if (img.empty())
    {
        cout << "Could not read input image file: " << inputImage << endl;
        return -1;
    }
 
    namedWindow("Image", 1);
    imshow("Image", img);
 
    namedWindow("Connected Components", 1);
    createTrackbar("Threshold", "Connected Components", &threshval, 255, on_trackbar);
    on_trackbar(threshval, 0);
 
    waitKey(0);
    return 0;
}