Opencv实现的简易绘图工具

来源:转载

第一次写博,还是个菜鸟。最近开始学习Opencv,试着写了个简易的绘图工具(目前只写了画线和橡皮擦部分,画其它图形还有待往里添加),也算是记录自己的学习之路。

#include "stdafx.h"#include "cv.h"#include "highgui.h"#define SHAPE_LINE 1#define SHAPE_ERASER 2int 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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