错误没有匹配的调用函数 - 即使更改为const xxxx＆amp;

Question

我是openCV的新手。我找到了我想要执行的特定代码：

https://gist.github.com/t-abe/1055619

我按照建议将第114行更改为 void mainLoop（const Func＆amp; func），但仍会收到以下错误：

  

error: no matching function for call to ‘InteractiveGrabcut::mainLoop(main()::<lambda(InteractiveGrabcut*, int)>)’ note: candidate is: note: template<class Func> void InteractiveGrabcut::mainLoop(const Func&)

我在这里不知所措。任何帮助将非常感激... 谢谢！

以下是代码：

#include <useopencv.h>
#include <string>
#include <vector>
#include <iostream>

class InteractiveGrabcut {
    cv::Mat src;
    cv::Mat fgd, bgd;
    bool ldrag, rdrag;
    std::string name;
public:
    cv::Mat mask;
    //cv::Rect rect;
    cv::Point lstart, rstart;
    cv::Scalar fg_color, bg_color;

    InteractiveGrabcut()
        : src(), mask(), fgd(), bgd(),
         ldrag(false), rdrag(false), name("igc"),
         fg_color(0, 0, 255), bg_color(255, 0, 0)
    {};

    InteractiveGrabcut(const cv::Mat& src_)
         : src(src_), mask(), fgd(), bgd(),
          ldrag(false), rdrag(false), name("igc"), fg_color(0, 0, 255), bg_color(255, 0, 0)
        {
            mask = cv::Mat::ones(src_.size(), CV_8U) * cv::GC_PR_BGD;
     };

    void prepareWindow(const std::string name){
    this->name = name;
    cv::namedWindow(name);
    cv::setMouseCallback(name, events, this);
};

static void events( int e, int x, int y, int flags, void* s ){
    InteractiveGrabcut* self = (InteractiveGrabcut*)s;
    cv::Point pt(x, y);
    switch(e) {
    case CV_EVENT_LBUTTONDOWN:
        self->ldrag = true;
        self->lstart = pt;
        break;
    case CV_EVENT_LBUTTONUP:
        self->ldrag = false;
        break;
    case CV_EVENT_RBUTTONDOWN:
        self->rdrag = true;
        self->rstart = pt;
        break;
    case CV_EVENT_RBUTTONUP:
        self->rdrag = false;
        break;
    case CV_EVENT_MOUSEMOVE:
        if(self->ldrag) {
            cv::line(self->mask, self->lstart, pt, cv::Scalar(cv::GC_FGD), 1);
            self->lstart = pt;
        }
        else if(self->rdrag) {
            cv::line(self->mask, self->rstart, pt, cv::Scalar(cv::GC_BGD), 1);
            self->rstart = pt;
        }
        break;
    default:
        break;
    };
};

void show(){
    cv::Mat scribbled_src = src.clone();
    const float alpha = 0.7f;
    for(int y=0; y < mask.rows; y++){
        for(int x=0; x < mask.cols; x++){
            if(mask.at<uchar>(y, x) == cv::GC_FGD) {
                cv::circle(scribbled_src, cv::Point(x, y), 2, fg_color, -1);
            } else if(mask.at<uchar>(y, x) == cv::GC_BGD) {
                cv::circle(scribbled_src, cv::Point(x, y), 2, bg_color, -1);
            } else if(mask.at<uchar>(y, x) == cv::GC_PR_BGD) {
                cv::Vec3b& pix = scribbled_src.at<cv::Vec3b>(y, x);
                pix[0] = (uchar)(pix[0] * alpha + bg_color[0] * (1-alpha));
                pix[1] = (uchar)(pix[1] * alpha + bg_color[1] * (1-alpha));
                pix[2] = (uchar)(pix[2] * alpha + bg_color[2] * (1-alpha));
            } else if(mask.at<uchar>(y, x) == cv::GC_PR_FGD) {
                cv::Vec3b& pix = scribbled_src.at<cv::Vec3b>(y, x);
                pix[0] = (uchar)(pix[0] * alpha + fg_color[0] * (1-alpha));
                pix[1] = (uchar)(pix[1] * alpha + fg_color[1] * (1-alpha));
                pix[2] = (uchar)(pix[2] * alpha + fg_color[2] * (1-alpha));
            }
        }
    }
    cv::imshow(name, scribbled_src);
    cv::imshow(name + "_FG", getFG());
}

void execute(){
    std::cout << "computing...";
    cv::grabCut(src, mask, cv::Rect(), bgd, fgd, 1, cv::GC_INIT_WITH_MASK);
    std::cout << "end." << std::endl;
};

cv::Mat getBinMask(){
    cv::Mat binmask(mask.size(), CV_8U);
    binmask = mask & 1;
    return binmask;
};

cv::Mat getFG(){
    cv::Mat fg = cv::Mat::zeros(src.size(), src.type());
    src.copyTo(fg, getBinMask());
    return fg;
};

    template <class Func>
    void mainLoop(Func& func){  //<------------------------
             //tried mainLoop(const Func& func)
             //      mainLoop(Func func) //no luck!
        while(1){
            int key = cv::waitKey(1);
           if(key == '\x1b')
               break;
           func(this, key);
          show();
        }
    };
};

    int main(){
    const std::string input_filename("bird.bmp");
    cv::Mat input_image = cv::imread(input_filename);

    InteractiveGrabcut igc(input_image);
    igc.prepareWindow("bird");
    igc.mainLoop([](InteractiveGrabcut* self, int key)->void {
       if(key == ' '){
          self->execute();
      }
    });
 }