opencv摄像头用法

python:

设置视频起始帧：

cap.set(cv2.CAP_PROP_POS_FRAMES, keys_frame) # keys_frame为关键帧的序号

  

   

    

     

    
    

     

      import cv2
     
    
   

    

     

    
    

     

      import numpy as numpy
     
    
   

    

     

    
    

     

      cap=cv2.VideoCapture(0)
     
    
   

    

     

    
    

     

      #设置显示分辨率和FPS ,不设置的话会非常卡
     
    
   

    

     

    
    

     

      cap.set(cv2.CAP_PROP_FRAME_WIDTH,800)
     
    
   

    

     

    
    

     

      cap.set(cv2.CAP_PROP_FRAME_HEIGHT,600)
     
    
   

    

     

    
    

     

      cap.set (cv2.CAP_PROP_FPS,20)
     
    
   

    

     

    
    

     

      while cap.isOpened():
     
    
   

    

     

    
    

     

       ret,frame=cap.read()
     
    
   

    

     

    
    

     
 # cv2.flip(frame,frame,1)
     
    
   

    

     

    
    

     
 # frame1=None
     
    
   

    

     

    
    

     
 # cv2.flip(frame,frame1,1)
     
    
   

    

     

    
    

     
 #图像水平翻转
     
    
   

    

     

    
    

     

       frame=cv2.flip(frame,1)
     
    
   

    

     

    
    

     
 # gray=cv2.cvtColor(frame,cv2.COLOR_BGR2RGB)
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

       cv2.imshow('camare',frame[0:100,1:200])
     
    
   

    

     

    
    

     
 #按Q键退出
     
    
   

    

     

    
    

     
 if cv2.waitKey(1) & 0xFF==ord('q'):
     
    
   

    

     

    
    

     
 break
     
    
   

    

     

    
    

     

      #释放摄像头和卸载窗口
     
    
   

    

     

    
    

     

      cap.release()
     
    
   

    

     

    
    

     

      cv2.destroyAllWindows()
     
    
  
 

c++打开摄像头： 

  

   

    

     

    
    

     

      #include<opencv2/core/core.hpp>
     
    
   

    

     

    
    

     

      #include<opencv2/highgui/highgui.hpp>
     
    
   

    

     

    
    

     

      #include<opencv2/imgproc/imgproc.hpp>
     
    
   

    

     

    
    

     

      #include<iostream>
     
    
   

    

     

    
    

     

      using namespace std;
     
    
   

    

     

    
    

     

      using namespace cv;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      int main()
     
    
   

    

     

    
    

     

      {
     
    
   

    

     

    
    

     
	//定义VideoCapture对象选择摄像头
     
    
   

    

     

    
    

     
	VideoCapture capture(0);
     
    
   

    

     

    
    

     
	//判断是否出错
     
    
   

    

     

    
    

     
	if (!capture.isOpened())
     
    
   

    

     

    
    

     

      	{
     
    
   

    

     

    
    

     
		cout << "some thing wrong" << endl;
     
    
   

    

     

    
    

     

      		system("pause");
     
    
   

    

     

    
    

     
		return -1;
     
    
   

    

     

    
    

     

      	}
     
    
   

    

     

    
    

     
	//获取视频相关信息---分辨率（宽、高）
     
    
   

    

     

    
    

     
	int  frameHeight = capture.get(CV_CAP_PROP_FRAME_HEIGHT);
     
    
   

    

     

    
    

     
	int frameWidth = capture.get(CV_CAP_PROP_FRAME_WIDTH);
     
    
   

    

     

    
    

     
	cout << "this video is :" << frameWidth << "*" << frameHeight << endl;
     
    
   

    

     

    
    

     
	//定义writer对象
     
    
   

    

     

    
    

     

      	VideoWriter outputVideo;
     
    
   

    

     

    
    

     

      	outputVideo.open("save.avi", -1, 25.0, Size(frameWidth, frameHeight), true);
     
    
   

    

     

    
    

     
	//判断open writer对象是否出错
     
    
   

    

     

    
    

     
	if (!outputVideo.isOpened()){
     
    
   

    

     

    
    

     
		cout << "fail to open the videowriter" << endl;
     
    
   

    

     

    
    

     

      		system("pause");
     
    
   

    

     

    
    

     
		return -1;
     
    
   

    

     

    
    

     

      	}
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
	//循环读取一帧
     
    
   

    

     

    
    

     

      	Mat frameImg;
     
    
   

    

     

    
    

     
	long nCount = 1;
     
    
   

    

     

    
    

     
	while (1){
     
    
   

    

     

    
    

     
		//输出当前帧数
     
    
   

    

     

    
    

     
		cout << "Current frame" << nCount << endl;
     
    
   

    

     

    
    

     

      		capture >> frameImg;
     
    
   

    

     

    
    

     
		//判断是否读完
     
    
   

    

     

    
    

     
		if (!frameImg.empty()){
     
    
   

    

     

    
    

     

      			imshow("frame", frameImg);
     
    
   

    

     

    
    

     

      		}
     
    
   

    

     

    
    

     
		else{
     
    
   

    

     

    
    

     
			break;
     
    
   

    

     

    
    

     

      		}
     
    
   

    

     

    
    

     
		//按Q退出
     
    
   

    

     

    
    

     
		if (char(waitKey(40) == 'q')){
     
    
   

    

     

    
    

     
			break;
     
    
   

    

     

    
    

     

      		}
     
    
   

    

     

    
    

     

      		outputVideo << frameImg;//将该帧写入文件
     
    
   

    

     

    
    

     

      		nCount++;
     
    
   

    

     

    
    

     

      	}
     
    
   

    

     

    
    

     
	//释放摄像头
     
    
   

    

     

    
    

     

      	capture.release();
     
    
   

    

     

    
    

     
	return 0;
     
    
   

    

     

    
    

     

      }
     
    
  
 

文章来源: blog.csdn.net，作者：网奇，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/jacke121/article/details/54377981