opencv3/C++实现视频读取、视频写入
时间：2020-11-24 16:33:25 | 栏目：Python代码 | 点击：次
视频读取
视频读取，主要利用VideoCapture类下的方法打开视频并获取视频中的帧，具体示例如下：
#include<iostream>
#include<opencv2/opencv.hpp>
using namespace cv;
int main()
{
VideoCapture capture;
Mat frame;
frame= capture.open("E:/image/a1.avi");
if(!capture.isOpened())
{
printf("can not open ...\n");
return -1;
}
namedWindow("output", CV_WINDOW_AUTOSIZE);
while (capture.read(frame))
{
imshow("output", frame);
waitKey(10);
}
capture.release();
return 0;
}
capture.open()的参数为0时为读取摄像头：
frame= capture.open(0);
视频写入
通过摄像头获取视频，然后通过capture.get(CV_CAP_PROP_FRAME_WIDTH), capture.get(CV_CAP_PROP_FRAME_HEIGHT)获取当前帧的宽度和高度，创建一个VideoWriter类对象writer进行视频的写入。
写入前可进行视频的简单处理。
#include<iostream>
#include<opencv2/opencv.hpp>
using namespace cv;
int main()
{
VideoCapture capture;
capture.open(0);
if(!capture.isOpened())
{
printf("can not open ...\n");
return -1;
}
Size size = Size(capture.get(CV_CAP_PROP_FRAME_WIDTH), capture.get(CV_CAP_PROP_FRAME_HEIGHT));
VideoWriter writer;
writer.open("E:/image/a2.avi", CV_FOURCC('M', 'J', 'P', 'G'), 10, size, true);
Mat frame, gray;
namedWindow("output", CV_WINDOW_AUTOSIZE);
while (capture.read(frame))
{
//转换为黑白图像
cvtColor(frame, gray, COLOR_BGR2GRAY);
//二值化处理
threshold(gray, gray, 0, 255, THRESH_BINARY | THRESH_OTSU);
cvtColor(gray, gray, COLOR_GRAY2BGR);
imshow("output", gray);
writer.write(gray);
waitKey(10);
}
waitKey(0);
capture.release();
return 0;
}
