如何使用opencv获取位置并绘制矩形

How can I get the position and draw rectangle using opencv?

本文关键字：绘制 位置 何使用 opencv 获取      更新时间：2023-10-16

我想在picturebox中移动并单击鼠标时获得一个位置我想在单击鼠标的时间和位置在图像窗口中创建矩形

我有一个来自文档的简单代码

#include "stdafx.h"
#include "opencv2/highgui/highgui.hpp"
#include <iostream>
using namespace std;
using namespace cv;
 
void CallBackFunc(int event, int x, int y, int flags, void* userdata)
{
    if ( event == EVENT_LBUTTONDOWN )
    {
        cout << "Left button of the mouse is clicked - position (" << x << ", " << y << ")" << endl;    
    }
    else if( event == EVENT_RBUTTONDOWN )
    {
        cout << "Right button of the mouse is clicked - position (" << x << ", " << y << ")" << endl;
    }
    else if( event == EVENT_MBUTTONDOWN )
    {
        cout << "Middle button of the mouse is clicked - position (" << x << ", " << y << ")" << endl;
    }
    else if ( event == EVENT_MOUSEMOVE )
    {
        cout << "Mouse move over the window - position (" << x << ", " << y << ")" << endl;
    }
}
int main(int argc, char** argv)
{
    bool isDragging = false;
    // Read image from file 
    Mat img = imread("input/pic1.jpg");
    //if fail to read the image
    if( img.empty() ) 
    { 
        cout << "Error loading the image" << endl;
        return -1; 
    }
    //Create a window
    namedWindow("My Window", 1);
    //set the callback function for any mouse event
    setMouseCallback("My Window", CallBackFunc, NULL);
    //show the image
    imshow("My Window", img);
    // Wait until user press some key
    waitKey(0);
    return 0;
}

它在windows form=上工作，但我想使用鼠标点击。我把代码放在GUI上。它抛出以下错误：

错误3错误C3867:"ProjectFinal:：MyForm:：CallBackFunc"：函数调用缺少参数列表；使用'&ProjectFinal:：MyForm:：CallBackFunc'创建指向成员c:\users\nugningz\documents\visual studio 2012\projects\ProjectFinal\ProjectFinal\MyForm.h 690 1 ProjectFinal 的指针

错误6错误C3867:"ProjectFinal:：MyForm:：CallBackFunc"：函数调用缺少参数列表；使用'&ProjectFinal:：MyForm:：CallBackFunc'创建指向成员c:\users\nugningz\documents\visual studio 2012\projects\ProjectFinal\ProjectFinal\MyForm.h 690 1 ProjectFinal 的指针

7 IntelliSense:指向成员的指针对于托管类c:\Users\NungNingZ\Documents\Visual Studio 2012\Projects\ProjectFinal\ProjectFinal\MyForm.h 690 37 ProjectFinal 无效

所以您有一个与您的问题无关的问题。

然而，您只需使用OpenCV highgui工具即可实现您的目标：

#include <opencv2opencv.hpp>
#include <iostream>
using namespace std;
using namespace cv;
vector<Rect> rects;
bool bDraw;
Rect r;
Point base;
Mat3b img;
Mat3b layer;
Mat3b working;

void CallBackFunc(int event, int x, int y, int flags, void* userdata)
{
    if ( event == EVENT_LBUTTONDOWN )
    {
        cout << "Left button of the mouse is clicked - position (" << x << ", " << y << ")" << endl;    
        // Init your rect
        base.x = x;
        base.y = y;
        r.x = x;
        r.y = y;
        r.width = 0;
        r.height = 0;
        bDraw = true;
    }        
    else if ( event == EVENT_MOUSEMOVE )
    {
        cout << "Mouse move over the window - position (" << x << ", " << y << ")" << endl;
        // If drawing, update rect width and height
        if(!bDraw) return;
        int dx = abs(r.x - x);
        int dy = abs(r.y - y);
        if(x < base.x) {
            r.x = x;
            r.width = abs(x - base.x);
        } else {
            r.width = dx;
        }
        if(y < base.y) {
            r.y = y;
            r.height = abs(y - base.y);
        } else {
            r.height = dy;
        }
        // Refresh
        working = layer.clone();
        rectangle(working, r, Scalar(0,255,0));
        imshow("My Window", working);
    }
    else if ( event == EVENT_LBUTTONUP)
    {
        cout << "Left button released" << endl;
        // Save rect, draw it on layer
        rects.push_back(r);
        rectangle(layer, r, Scalar(0,255,255));
        r = Rect(); 
        bDraw = false;
        // Refresh
        working = layer.clone();
        rectangle(working, r, Scalar(0,255,0));
        imshow("My Window", working);
    }
}
int main(int argc, char** argv)
{
    bool bDraw = false;
    bool isDragging = false;
    // Read image from file 
    img = imread("path_to_image");
    // initialize your temp images
    layer = img.clone();
    working = img.clone();
    //if fail to read the image
    if( img.empty() ) 
    { 
        cout << "Error loading the image" << endl;
        return -1; 
    }
    //Create a window
    namedWindow("My Window", 1);
    //set the callback function for any mouse event
    setMouseCallback("My Window", CallBackFunc, NULL);
    //show the image
    imshow("My Window", working);
    // Wait until user presses 'q'
    while((waitKey(1) & 0xFF) != 'q');
    return 0;
}

在opencv-contrib的tracking模块中，有一个很好的selectROI特性。

#include <opencv2/opencv.hpp>
// selectROI is part of tracking API
#include <opencv2/tracking.hpp>
using namespace std;
using namespace cv;

int main (int argc, char **arv)
{
    // Read image
    Mat im = imread("image.jpg");
    // Select ROI
    Rect2d r = selectROI(im, false); // false -> for creating rectangle from 
                                     //          top-left to bottom-right
    // Crop image
    Mat imCrop = im(r);
    // Display Cropped Image
    imshow("Image", imCrop);
    waitKey(0);
    return 0;
}

使用鼠标选择ROI(感兴趣区域(，然后按SPACE或ENTER按钮。按c按钮取消选择过程。

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