学习OpenCV-例程实践（持续更新）

た入场券 2022-03-31 11:51 175阅读 0赞

例4-1：用鼠标在窗口中画方形的程序

#include"pch.h"//看情况加
    #include <cv.h>
    #include <highgui.h>
    
    CvRect box;	//定义绘制的矩形
    bool drawing_box = false;	//状态-鼠标正在移动
    
    void draw_box(IplImage* img, CvRect rect){
    	//绘制矩形
    	cvRectangle(
    	img, cvPoint(rect.x, rect.y), cvPoint(rect.x+ rect.width, rect.y+ rect.height),
    	cvScalar(0xff,0xf0,0x0f));
    }
    
    //鼠标响应函数-回调函数
    void my_mouse_callback(
    	int event, int x, int y, int flags, void* param)
    {
    	IplImage* img = (IplImage*)param;
    
    	switch (event)
    	{
    	case CV_EVENT_MOUSEMOVE: 	//mouse move 
    		if (drawing_box) {
    			box.width = x - box.x;
    			box.height = y - box.y;
    		}
    
    		break;
    	case CV_EVENT_LBUTTONDOWN: 	//left button be pressed
    		drawing_box = true;		//drawing flag set 1
    		box = cvRect(x, y, 0, 0);
    
    		break;
    	case CV_EVENT_LBUTTONUP: 	//left button be released
    		drawing_box = false;
    		// redefine the left position of box
    		if (box.width < 0) {
    			box.x += box.width;
    			box.width *= -1;
    		}
    		if (box.height < 0) {
    			box.y += box.height;
    			box.height *= -1;
    		}
    		draw_box(img, box);	// draw the box ,the img is a inside var
    
    		break;
    	}
    }
    
    
    
    int main(int argc, char** argv[])
    {
    	box = cvRect(-1, -1, 0, 0);//设置一个矩形，被隐藏
    
    	IplImage *img = cvCreateImage(cvSize(2000, 2000), IPL_DEPTH_8U, 3);//创建一个图像
    	cvZero(img);//数据设置为0
    	IplImage* temp = cvCloneImage(img);	//copy image,copy the struction
    	cvNamedWindow("Box Example");	//build a windown with box example
    	
    	//set mouse callback function 
    	cvSetMouseCallback(
    		"Box Example",
    		my_mouse_callback,//the second para. only need pointer address 
    		(void*)img);
    	
    	while (1){
    		cvCopy(img, temp);//copy image from imag to temp
    		if (drawing_box)	
    			draw_box(temp, box);
    		cvShowImage("Box Example", temp);
    		
    		if (cvWaitKey(15) == 27) break;
    	}
    	cvReleaseImage( &img );
    	cvReleaseImage( &temp );
    	cvDestroyWindow("Box Example");
    }

练习4-1

//三张合成的位置出现错误。文字还是有点问题
    
    #include"pch.h"
    #include <cv.h>
    #include <highgui.h>
    
    int main(int argc, char** argv)
    {
    	//加载视频文件
    	CvCapture* capture = cvCreateFileCapture("D:\\Project Files\\VS\\opencv\\ConsoleApplication1\\test.avi");
    	//创建窗口
    	cvNamedWindow("origin", CV_WINDOW_AUTOSIZE);
    	cvNamedWindow("gray", CV_WINDOW_AUTOSIZE);
    	cvNamedWindow("canny", CV_WINDOW_AUTOSIZE);
    	cvNamedWindow("totle", CV_WINDOW_AUTOSIZE);
    
    	//获取视频的大小
    	CvSize size = cvSize((int)cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_WIDTH),
    		(int)cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_HEIGHT));
    	
    	//创建图像结构-用于存放图像信息
    	IplImage* gray = cvCreateImage(size, IPL_DEPTH_8U, 1);
    	IplImage* gray3 = cvCreateImage(size, IPL_DEPTH_8U, 3);		//三通道灰度图像
    	IplImage* cannyImage = cvCreateImage(size, IPL_DEPTH_8U, 1);
    	IplImage* cannyImage3 = cvCreateImage(size, IPL_DEPTH_8U, 3);//三通道canny图像
    	//size.width = size.width*3;
    	IplImage* totle = cvCreateImage(cvSize(size.width * 3, size.height), IPL_DEPTH_8U, 3);
    	cvZero(totle);
    
    	while (1)
    	{
    		IplImage* frame = cvQueryFrame(capture);
    
    		if (!frame)
    		{
    			return -1;
    		}
    
    		cvShowImage("origin", frame);
    		//转化为gray格式-灰度值
    		cvConvertImage(frame, gray, 0);
    
    		cvShowImage("gray", gray);
    
    		//做canny运算
    		//边缘操作必须是单通道-灰度值
    		if (gray->nChannels != 1)
    		{
    			break;
    		}
    		cvCanny(gray, cannyImage, 100, 150, 3);
    
    		cvShowImage("canny", cannyImage);
    
    		//将三个图放在一个窗口中--利用指针头
    		IplImage* img1 = cvCreateImageHeader(size, frame->depth, 3);
    		IplImage* img2 = cvCreateImageHeader(size, frame->depth, 3);
    		IplImage* img3 = cvCreateImageHeader(size, frame->depth, 3);
    		img1->origin = frame->origin;
    		img1->widthStep = totle->widthStep;//这里注意，因为img1要成为在大图中的一部分，所以是大图每行字节长
    
    
    		img2->origin = frame->origin;
    		img2->widthStep = totle->widthStep;
    
    		img3->origin = frame->origin;
    		img3->widthStep = totle->widthStep;
    
    		//转化为三通道图像
    		cvCvtColor(gray, gray3, CV_GRAY2BGR);
    		cvCvtColor(cannyImage, cannyImage3, CV_GRAY2BGR);
    
    
    		img1->imageData = totle->imageData; //第一个指向大图的开始处，即第一行
    		cvCopy(frame, img1);
    
    		img2->imageData = totle->imageData + frame->widthStep;//这里很关键，注意字节排列问题，所以不能用width
    		cvCopy(gray3, img2);
    
    		img3->imageData = totle->imageData + 2 * frame->widthStep;
    		cvCopy(cannyImage3, img3);
    
    
    		CvFont font = cvFont(10.0, 1);
    		cvInitFont(&font, CV_FONT_HERSHEY_SCRIPT_SIMPLEX, 0.5f, 0.5f, 0, 1);
    		cvPutText(totle, "Frame", cvPoint(10, 20), &font, cvScalar(0, 0, 255));
    		cvPutText(totle, "Frame_gray", cvPoint(10 + size.width, 20), &font, cvScalar(0, 0, 255));
    		cvPutText(totle, "Frame_canny", cvPoint(10 + size.width * 2, 20), &font, cvScalar(0, 0, 255));
    
    		cvShowImage("totle", totle);
    		char c = cvWaitKey(33);
    		if (c == 27)
    		{
    			break;
    		}
    	}
    
    	cvReleaseCapture(&capture);
    	cvReleaseImage(&gray);
    	//cvReleaseImage(&gray);
    	cvReleaseImage(&cannyImage);
    	cvReleaseImage(&totle);
    	cvReleaseImage(&gray3);
    	cvReleaseImage(&cannyImage3);
    	cvDestroyAllWindows();
    
    	return 1;
    
    }