画板功能主要包括：
- 右键切换橡皮擦
- 左键画圆，椭圆，矩形，直线
- 键盘输入进行图形的切换
- 其他功能自己可以自行添加
具体实现显示如下：
代码贴出：
代码语言：javascript复制#include <iostream>
#include <opencv2/opencv.hpp>
#include <cmath>
using namespace std;
using namespace cv;
Rect box;
bool drawing_box = false;
Rect Eraser;
bool drawing_eraser = false;
int Eraser_Size = 5;
bool drawing_circle= false;
bool drawing_line =false;
bool drawing_ellipse=false;
//形状切换
bool mode_r = true;
bool mode_l = true;
bool mode_c = true;
bool mode_e = true;
void mouse_paint_callback(int event,
int x,
int y,
int flags,
void* param
);
//画矩形
void draw_box( Mat img, CvRect box)
{
rectangle(img,
Point(box.x,box.y),
Point(box.x box.width,box.y box.height),
Scalar(0,255,0) ,
3
);
}
//画圆
void draw_circle( Mat img, CvRect box)
{
circle(img,
Point(box.x,box.y),
sqrt(box.width*box.width box.height*box.height),
Scalar(0,0,255)
);
}
//画直线
void draw_line(Mat img,CvRect box)
{
line(img,Point(box.x,box.y),Point((box.x box.width),(box.y box.height)),cv::Scalar(255,0,0),3 );
}
//椭圆
void draw_ellipse(Mat img,CvRect box)
{
cv::Point center(box.x,box.y);
cv::Size axes(20, 10);
cv::ellipse(img, center, axes,0, 0, 360.0, cv::Scalar(20,0,100), 2);
}
void draw_Eraser( Mat img, CvRect Eraser)
{
rectangle(img,
Point(Eraser.x - Eraser_Size,Eraser.y - Eraser_Size),
Point(Eraser.x Eraser_Size,Eraser.y Eraser_Size),
Scalar(0xff,0xff,0xff),
CV_FILLED
);
}
void show_Eraser( Mat img, CvRect Eraser)
{
rectangle(img,
Point(Eraser.x - Eraser_Size,Eraser.y - Eraser_Size),
Point(Eraser.x Eraser_Size,Eraser.y Eraser_Size),
Scalar(255,255,255),
CV_FILLED
);
}
void draw_draw(int x,int y,int flags)
{
if((flags & CV_EVENT_FLAG_SHIFTKEY) == CV_EVENT_FLAG_SHIFTKEY)
{
if (box.x>box.y)
{
box.width = x - box.x;
box.height= (y - box.y > 0)?abs(y - box.y):-abs(y - box.y);
}
else
{
box.width = (x - box.x > 0)?abs(x - box.x):-abs(x - box.x);
box.height= y - box.y;
}
}
else
{
box.width = x - box.x;
box.height= y - box.y;
}
}
int main()
{
box = Rect(-1, -1, 0, 0);
Eraser = Rect(-1, -1, 0, 0);
Mat srcImage(600, 800, CV_8UC3);
srcImage.setTo(Scalar(255,255,255)); //设置背景色颜色为白色
Mat tempImage;
srcImage.copyTo(tempImage);
namedWindow("drawing");
setMouseCallback("drawing",mouse_paint_callback,(void*)&srcImage);
while(1)
{
srcImage.copyTo(tempImage);
if(drawing_circle) draw_circle(tempImage,box);
if(drawing_box) draw_box(tempImage,box);
if(drawing_line) draw_box(tempImage,box);
if(drawing_ellipse) draw_box(tempImage,box);
if(drawing_eraser) show_Eraser(tempImage,Eraser);
imshow("drawing",tempImage);
if (cvWaitKey(1)=='c') mode_r=false, mode_l=false,mode_e=false,mode_c=true;
if (cvWaitKey(1)=='r') mode_r=true, mode_l=false,mode_e=false,mode_c=false;
if (cvWaitKey(1)=='l') mode_r=false, mode_l=true,mode_e=false,mode_c=false;
if (cvWaitKey(1)=='e') mode_r=false, mode_l=false,mode_e=true,mode_c=false;
if(cvWaitKey(15) == 27) break;
}
return 0;
}
void mouse_paint_callback(int event,
int x,
int y,
int flags,
void* param
)
{
Mat& image = *(cv::Mat*)param;
if ( event==CV_EVENT_MOUSEMOVE)
{
if(drawing_box)
{
draw_draw(x,y,flags);
}
if(drawing_circle)
{
draw_draw(x,y,flags);
}
if(drawing_line)
{
draw_draw(x,y,flags);
}
if(drawing_ellipse)
{
draw_draw(x,y,flags);
}
if(drawing_eraser)
{
Eraser = cvRect(x,y,0,0);
Eraser = cvRect(x,y,0,0);
draw_Eraser(image,Eraser); //用黑色方块表示一个橡皮擦
}
}
else if( event==CV_EVENT_LBUTTONDOWN) //左键压下
{
if (mode_r == true)
{
drawing_box = true;
box = Rect(x,y,0,0);
}
if (mode_c == true)
{
drawing_circle = true;
box = Rect(x,y,0,0);
}
if (mode_l == true)
{
drawing_line = true;
box = Rect(x,y,0,0);
}
if (mode_e == true)
{
drawing_ellipse = true;
box = Rect(x,y,0,0);
}
}
else if ( event==CV_EVENT_RBUTTONDOWN) //右键压下
{
drawing_eraser = true;
Eraser = Rect(x,y,0,0);
draw_Eraser(image,Eraser);
}
else if ( event==CV_EVENT_LBUTTONUP) //左键弹起
{
drawing_box = false;
drawing_circle = false;
drawing_line = false;
drawing_ellipse = false;
if(box.width<0)
{
box.x = box.width;
box.width *= -1;
}
if(box.height<0)
{
box.y = box.height;
box.height *= -1;
}
if (mode_r == true )
draw_box(image,box);
if (mode_c ==true )
draw_circle(image,box);
if (mode_l == true )
draw_line(image,box);
if (mode_e ==true )
draw_ellipse(image,box);
}
else if ( event==CV_EVENT_RBUTTONUP)//右键弹起
{
drawing_eraser = false;
}
}
博主：菜鸟程序员
初衷：学习资料，程序设计，图像处理，视觉算法，求职经验，工作心得
