如何使 cv::setMouseCallback 函数工作
How to make cv::setMouseCallback function work
我见过几个可能相同的问题。阅读答案后，我仍然无法使我的代码工作。因此，如果我重复这些帖子，我提前表示歉意。
我设法编写了这段代码：
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>
#include <string>
bool leftButtonDown = false, leftButtonUp = false;
cv::Mat img;
cv::Point cor1, cor2;
cv::Rect rect;
void mouseCall(int event, int x, int y, int, void*) {
if (event == cv::EVENT_LBUTTONDOWN) //finding first corner
{
leftButtonDown = true; cor1.x = x; cor1.y = y; std::cout << "Corner 1: " << cor1 << std::endl;
}
if (event == cv::EVENT_LBUTTONUP) {
if (abs(x - cor1.x)>20 && abs(y - cor1.y)>5) //finding second corner and checking whether the region is too small
{
leftButtonUp = true; cor2.x = x; cor2.y = y; std::cout << "Corner 2: " << cor2 << std::endl;
}
else { std::cout << "Select more than 5 pixels" << std::endl; }
}
if (leftButtonDown == true && leftButtonUp == false) //when the left button is clicked and let off
{ //draw a rectangle continuously
cv::Point pt; pt.x = x; pt.y = y;
cv::Mat temp_img = img.clone();
rectangle(temp_img, cor1, pt, cv::Scalar(0, 0, 255));
cv::imshow("Original", temp_img);
}
else if (event == cv::EVENT_MOUSEMOVE) //tracking mouse movement
{
std::cout << "Mouse moving over the window - position (" << x << ", " << y << ")" << std::endl;
}
if (leftButtonDown == true && leftButtonUp == true) //when the selection is done
{
rect.width = abs(cor1.x - cor2.x);
rect.height = abs(cor1.y - cor2.y);
rect.x = cv::min(cor1.x, cor2.x);
rect.y = cv::min(cor1.y, cor2.y);
cv::Mat cutTempImg(img, rect); //Selecting a ROI(region of interest) from the original img
cv::namedWindow("Cut Temporary Image");
cv::imshow("Cut Temporary Image", cutTempImg); //showing the cropped image
leftButtonDown = false;
leftButtonUp = false;
}
}
int main(){
img = cv::imread("image.jpg");
cv::namedWindow("Original");
cv::imshow("Original", img);
cv::setMouseCallback("Original", mouseCall); //setting the mouse callback for selecting the region with mouse
while (char(cv::waitKey(1) != 'q')) //waiting for the 'q' key to finish the execution
{
}
return 0;
}
而且它工作正常。现在我想使用class.（OOP）制作相同的代码。
但cv::setMouseCallback功能是不允许我这样做。任何人都可以帮我解决这个问题吗？
我的第二个代码：
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>
#include <string>
class ResizeImage {
cv::Mat img;
cv::Point cor1, cor2;
cv::Rect rect;
std::string name;
public:
void setImg(cv::Mat img) { this->img = img; };
cv::Mat getImg() { return img; };
void setRect();
int getCoordinates1X() { return cor1.x; };
int getCoordinates1Y() { return cor1.y; };
int getCoordinates2X() { return cor2.x; };
int getCoordinates2Y() { return cor2.y; };
void setCoordinates1(int x, int y) { this->cor1.x = x; this->cor1.y = y; };
void setCoordinates2(int x, int y) { this->cor2.x = x; this->cor2.y = y; };
void mouseCall(int event, int x, int y, int flags, void* param);
void showImgOriginal();
void setImgName(std::string name) { this->name = name; };
std::string getImgName() { return name; };
};
void ResizeImage :: showImgOriginal() {
cv::namedWindow(name, CV_WINDOW_AUTOSIZE);
cv::imshow(name, img);
};
void ResizeImage::setRect() {
rect.width = abs(cor1.x - cor2.x);
rect.height = abs(cor1.y - cor2.y);
rect.x = cv::min(cor1.x, cor2.x);
rect.y = cv::min(cor1.y, cor2.y);
}
void ResizeImage::mouseCall(int event, int x, int y, int flags, void* param) {
if (event == cv::EVENT_LBUTTONDOWN) //finding first corner
{
leftButtonDown = true; setCoordinates1(x,y); std::cout << "Corner 1: " << getCoordinates1X()<<" "<<getCoordinates1Y() << std::endl;
}
if (event == cv::EVENT_LBUTTONUP) {
if (abs(x - cor1.x)>20 && abs(y - cor1.y)>5) //finding second corner and checking whether the region is too small
{
leftButtonUp = true; setCoordinates2(x, y); std::cout << "Corner 2: " << getCoordinates2X() << " " << getCoordinates2Y() << std::endl;
}
else { std::cout << "Select more than 5 pixels" << std::endl; }
}
if (leftButtonDown == true && leftButtonUp == false) //when the left button is down
{
cv::Point pt; pt.x = x; pt.y = y;
cv::Mat temp_img = img.clone();
rectangle(temp_img, cor1, pt, cv::Scalar(0, 0, 255)); //drawing a rectangle continuously
cv::imshow("Original", temp_img);
}
else if (event == cv::EVENT_MOUSEMOVE) //tracking mouse movement
{
std::cout << "Mouse moving over the window - position (" << x << ", " << y << ")" << std::endl;
}
if (leftButtonDown == true && leftButtonUp == true) //when the selection is done
{
setRect();
cv::Mat cutTempImg(img, rect); //Selecting a ROI(region of interest) from the original img
cv::namedWindow("Cut Temporary Image");
cv::imshow("Cut Temporary Image", cutTempImg); //showing the cropped image
leftButtonDown = false;
leftButtonUp = false;
}
}
int main(){
cv::Mat img = cv::imread("image.jpg");
ResizeImage img_;
img_.setImg(img);
img_.setImgName("original");
img_.showImgOriginal();
cv::setMouseCallback(img_.getImgName(),img_.mouseCall());
while (char(cv::waitKey(1) != 'q')) //waiting for the 'q' key to finish the execution
{
}
return 0;
}
更改后的代码：
//Program is loading image, and showing it to user.
//User can use mouse to make a rectangle and cut the loaded image.
//Command line is tracking mouse movements and the coordinates of the rectangle.
//User can end the program using 'q'.
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>
#include <string>
bool leftButtonDown = false, leftButtonUp = false; //flags for mouse clicks
class ResizeImage {
cv::Mat img; //image to process
cv::Point cor1, cor2; //coordinates of selected rectangle
cv::Rect rect; //rectangle
std::string name; //windows name
public:
//////////////////////////////////////////////////////////////////////////////
ResizeImage() { std::cout << "Starting..."<<std::endl; }; //Constructor/Destructor
~ResizeImage() { std::cout << "Ending..." << std::endl; };
//////////////////////////////////////////////////////////////////////////////
void setImg(cv::Mat img) { this->img = img; };
void setImgName(std::string name) { this->name = name; }; //set functions
void setRect();
void setCoordinates1(int x, int y) { this->cor1.x = x; this->cor1.y = y; };
void setCoordinates2(int x, int y) { this->cor2.x = x; this->cor2.y = y; };
//////////////////////////////////////////////////////////////////////////////
int getCoordinates1X() { return cor1.x; }; //getfunctions
int getCoordinates1Y() { return cor1.y; };
int getCoordinates2X() { return cor2.x; };
int getCoordinates2Y() { return cor2.y; };
cv::Mat getImg() { return img; };
std::string getImgName() { return name; };
//////////////////////////////////////////////////////////////////////////////
static void mouseCall(int event, int x, int y, int flags, void* param); //static function
//////////////////////////////////////////////////////////////////////////////
void showImgOriginal(); //show function (priting image)
//////////////////////////////////////////////////////////////////////////////
};
void ResizeImage :: showImgOriginal() { //showing image
cv::namedWindow(name, CV_WINDOW_AUTOSIZE);
cv::imshow(name, img);
};
void ResizeImage::setRect() { //calculating selected rectangle
rect.width = abs(cor1.x - cor2.x);
rect.height = abs(cor1.y - cor2.y);
rect.x = cv::min(cor1.x, cor2.x);
rect.y = cv::min(cor1.y, cor2.y);
}
void ResizeImage::mouseCall(int event, int x, int y, int flags, void* param) {
if (event == cv::EVENT_LBUTTONDOWN) //finding first corner
{
leftButtonDown = true; ((ResizeImage*)param)->cor1.x = x; ((ResizeImage*)param)->cor1.y = y; //saving coordinates
std::cout << "Corner 1: " << ((ResizeImage*)param)->cor1.x << " " << ((ResizeImage*)param)->cor1.y << std::endl; //printing coordinates
}
if (event == cv::EVENT_LBUTTONUP) {
if (abs(x - ((ResizeImage*)param)->cor1.x)>20 && abs(y - ((ResizeImage*)param)->cor1.y)>10) //finding second corner and checking whether the region is too small
{
leftButtonUp = true; ((ResizeImage*)param)->cor2.x = x; ((ResizeImage*)param)->cor2.y = y; //saving coordinates
std::cout << "Corner 2: " << ((ResizeImage*)param)->cor2.x << " " << ((ResizeImage*)param)->cor2.y << std::endl; //printing coordinates
}
else { std::cout << "Select more than 10 pixels" << std::endl; } //warning if region is too small
}
if (leftButtonDown == true && leftButtonUp == false) //when the left button is down
{
cv::Point pt; pt.x = x; pt.y = y;
cv::Mat temp_img = ((ResizeImage*)param)->img.clone();
rectangle(temp_img, ((ResizeImage*)param)->cor1, pt, cv::Scalar(0, 0, 255)); //drawing a rectangle continuously
}
else if (event == cv::EVENT_MOUSEMOVE) //tracking mouse movement
{
std::cout << "Mouse moving over the window - position (" << x << ", " << y << ")" << std::endl;
}
if (leftButtonDown == true && leftButtonUp == true) //when the selection is done
{
((ResizeImage*)param)->setRect();
cv::Mat cutTempImg(((ResizeImage*)param)->img, ((ResizeImage*)param)->rect); //Selecting a ROI(region of interest) from the original img
cv::namedWindow("Cut Temporary Image");
cv::imshow("Cut Temporary Image", cutTempImg); //showing the cropped image
leftButtonDown = false;
leftButtonUp = false;
}
}
int main() {
cv::Mat img = cv::imread("image.jpg");
ResizeImage img_;
img_.setImg(img);
img_.setImgName("Original");
img_.showImgOriginal();
cv::setMouseCallback(img_.getImgName(),ResizeImage::mouseCall,&img_);
while (char(cv::waitKey(1) != 'q')) //waiting for the 'q' key to finish the execution
{
}
return 0;
}
如果要使用类方法作为回调，确实应该将该方法声明为static。但是，您还需要将对象传递给回调，以便能够访问类的非静态成员，例如 cor1 或 cor2 。
下面是如何实现此目的的最小示例：
class Call {
public:
Call(int i) : a(i){};
int a;
static void mouse(int event, int x, int y, int flags, void* param) {
std::cout << ((Call*)param)->a << std::endl;
}
};
cv::namedWindow("Call");
Call call(10);
cv::setMouseCallback("Call", Call::mouse, &call);
cv::imshow("Call", cv::Mat(100, 100, CV_8U, cv::Scalar(0)));
cv::waitKey();
我创建了一个Call对象，并使用其mouse方法作为窗口回调，同时仍然将对象传递给回调。
你应该使函数static：
static void mouseCall(int event, int x, int y, int flags, void* param);
然后：
cv::setMouseCallback(img_.getImgName(),ResizeImage::mouseCall);
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- 如何使 cv::setMouseCallback 函数工作
