#include <iostream>
#include <opencv2/opencv.hpp>
using namespace cv;//包含cv命名空间
int main() {//imread(path)：从给定路径读取一张图片，储存为Mat变量对象Mat img = imread("images/love.jpg");//namedWindow(window):定义一个显示窗口并指定窗口名namedWindow("love");//imshow(window,img)，在指定窗口显示指定图像imshow("love", img);//waitKey(millisecond),等待按键输入后退出，指定时间（ms）后自动关闭窗口，second=0表示无限等待waitKey(0);//关闭所有窗口，释放资源destroyAllWindows();return 0;
}
Open CV C++显示视频
#include <iostream>
#include <opencv2/opencv.hpp>using namespace std;
using namespace cv;//包含cv命名空间int main() {//显示视频//创建视频捕获对象VideoCapture cap;//选择视频源//1.使用摄像头（默认摄像头，设备索引0）cap.open(0);//2.使用视频文件cap.open("videos/example1.mp4");//检查是否成功打开视频源if (!cap.isOpened()) {cerr << "Error: Could not open video source!" << endl;return -1;}//创建窗口(按照图像实际尺寸显示)namedWindow("Video Player", WINDOW_AUTOSIZE);// 视频帧率信息（可选）,实际帧率 = min(视频源帧率, 1000/delay, 处理能力上限)double fps = cap.get(CAP_PROP_FPS);cout << "Frame rate: " << fps << " FPS" << endl;//主循环：逐帧读取和显示while (true) {Mat frame;//从视频源读取一帧cap >> frame;//检查是否读取到有效帧if (frame.empty()) { cerr << "End of video stream" << endl; break;}//显示当前帧imshow("Video Player", frame);//检查按键输入（按ESC键退出）char key = waitKey(25); //25ms延迟=40 FPSif (key == 27) { // ASCII码27=ESC键cout << "Exit by user request" << endl;break;}}// 释放资源cap.release();destroyAllWindows();return 0;
}
Open CV Python显示图像
import cv2
import numpy as np#显示图像
def show_image(img_path):#读取图像->np.ndarrayimg=cv2.imread(img_path)#定义命名一个图像显示窗口cv2.namedWindow("Cute")#在指定窗口显示图像cv2.imshow("Cute",img)#等待任意按键退出cv2.waitKey(0)#关闭所有窗口cv2.destroyAllWindows()show_image("images/cute.jpg")
Open CV Python显示视频
import cv2
import numpy as npdef show_video(video_path,device_idx=0,window_name="Video",target_fps=30):#创建视频捕获对象cap = cv2.VideoCapture()#选择视频源（摄像头或视频文件）,device_idx=-1表示显示视频文件#1.摄像头（默认摄像头索引为0）if device_idx!=-1 and not video_path:cap.open(device_idx)#2.视频文件else:cap.open(video_path)#检测视频源是否存在if not cap.isOpened():print(f"Error : Could not open video source!")return#定义视频播放窗口cv2.namedWindow(window_name,cv2.WINDOW_AUTOSIZE)#主循环:逐帧读取和显示while True:ret, frame = cap.read() #ret:bool，视频帧读取是否成功；frame:视频帧图像#判断视频帧是否有效if not ret:print(f"End of video stream!")breakcv2.imshow(window_name,frame) #显示视频帧#按ESC键退出，控制视频帧率key=cv2.waitKey(target_fps)if key == 27:print("Exit by user request!")break#释放资源cap.release()cv2.destroyAllWindows()#显示示例视频
show_video(video_path="videos/example.mp4",window_name="Example Video",target_fps=40)
