Opencv实现的简易绘图工具

来源：互联网发布：js调用手写输入法编辑：程序博客网时间：2024/06/05 07:53
#include "stdafx.h"
#include "cv.h"
#include "highgui.h"
 
#define SHAPE_LINE 1
#define SHAPE_ERASER 2
 
int g_style;
CvRect rect;
 
CvPoint g_StartPoint;  
CvPoint g_EndPoint;
CvPoint p_Start;       //记录鼠标位置左上方点
CvPoint p_End;          //记录鼠标位置右下方点
bool drawing=false;       //是否处于画图状态
bool erasering=false;    //是否处于擦除状态
 
void callback(int event,int x,int y,int flags,void* param);
void DrawLine(IplImage* img);
//简易绘图工具，实现了画线和橡皮擦功能，绘图功能还有待往里添加
int main(int argc,char** argv)
{
    IplImage* img=cvCreateImage(cvSize(512,512),IPL_DEPTH_8U,3);
    cvSet(img,cvScalar(255,255,255));
 
    IplImage* temp=cvCloneImage(img);
    cvCopy(img,temp);
 
    cvNamedWindow("简易绘图工具");
 
    cvSetMouseCallback("简易绘图工具",callback,img);
    printf("请键入要选择执行的操作:‘l’——”画线“,‘e’——”橡皮“\n");
    char select='l';
 
    while(1)
    {
        cvCopyImage(img,temp);      //始终在原图image上画结果(和鼠标事件绑定)，先将image复制给temp,然后在临时图temp画出画图的过程(在main函数中画过程图形),然后用temp来显示图像
        switch(select)
        {
        case 'l':
            g_style=SHAPE_LINE;
            break;
        case 'e':
            g_style=SHAPE_ERASER;
            break;
        case 27:
            return 0;
        }
        if(g_style==SHAPE_LINE&&drawing)     //画鼠标在按住移动过程中画线
            cvDrawLine(temp,g_StartPoint,g_EndPoint,cvScalar(0,0,0));
        if(g_style==SHAPE_ERASER)  
        {
            cvRectangle(temp,p_Start,p_End,cvScalar(0,0,0));  //画出橡皮矩形边框
        }
        cvShowImage("简易绘图工具",temp);
        select=cvWaitKey(30);
    }
    cvReleaseImage(&img);
    cvReleaseImage(&temp);
    cvDestroyWindow("简易绘图工具");
    return 0;
}
 
void callback(int event,int x,int y,int flags,void* param)
{
    IplImage* img=(IplImage*)param;
 
    switch(event)
    {
    case CV_EVENT_LBUTTONDOWN:
        {
            if(SHAPE_LINE==g_style)  
            {
                drawing=true;
                g_StartPoint=cvPoint(x,y);
                g_EndPoint=g_StartPoint;   //此处将终点坐标设为同起始点避免记住前一条直线的终点坐标
            }
            if(SHAPE_ERASER==g_style)
            {
                erasering=true;
                //注意边界问题要适当修改ROI有效区域
                rect.x=x-20;  rect.y=y-20;      //注意坐标的计算,一般原点在窗口的左上角(这和操作系统等因素有关,IplImage结构中有个origin属性可以设置图像的原点)
                rect.width=40;  rect.height=40;
                p_Start.x=x-20; p_Start.y=y-20;
                p_End.x=x+20;   p_End.y=y+20;
                if(x>-20&&x<532&&y>-20&&y<532)
                {
                    cvSetImageROI(img,rect);
                    cvSet(img,cvScalar(255,255,255));
                    cvResetImageROI(img);
                }
            }
        }
        break;
    case CV_EVENT_MOUSEMOVE:
        {
            p_Start.x=x-20; p_Start.y=y-20;      //随时定位鼠标位置画橡皮矩形
            p_End.x=x+20;   p_End.y=y+20;
            if(SHAPE_LINE==g_style)
            {
                if(drawing)
                {
                    g_EndPoint=cvPoint(x,y);
                }
            }
 
            if(SHAPE_ERASER==g_style)
            {
                rect.x=x-20;  rect.y=y-20;   
                rect.width=40;  rect.height=40;
                if(erasering)
                {
                    if(x>-20&&x<532&&y>-20&&y<532)
                    {
                        cvSetImageROI(img,rect);
                        cvSet(img,cvScalar(255,255,255));
                        cvResetImageROI(img);
                    }
                }
            }
 
        }
        break;
    case CV_EVENT_LBUTTONUP:
        {
            if(SHAPE_LINE==g_style)
            {
                drawing=false;
                cvDrawLine(img,g_StartPoint,g_EndPoint,cvScalar(255,0,0));  //(255,0,0)此处画出的是蓝色,即BGR
            }
 
            if(SHAPE_ERASER==g_style)
            {
                erasering=false;
            }
        }
    }
}
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