007_OpenCV_Capture_Camera_Video.md

OpenCV Capture Camera Video

Use OpenCV to capture computer's camera and show the video.

Requirements

1. It'll open the computer's camera and show the video in a window.
2. When you press "q" key it'll quit.

What will we practice in this project?

• OpenCV: you need to install the opencv-python package via pip install opencv-python command in this project environment.
• while loop
• if condition
• keyboard check

A reference code

import cv2

# Open your computer's default camera device.
# If your default camera ID is not 0, please use the correct ID
camera = cv2.VideoCapture(0)

# while loop to read the camera image
while True:
    success, img = camera.read()
    # if read success, it'll show the image in a "Video" window
    if success:
        cv2.imshow('Video', img)
    # get the key press, if you pressed "q" key it'll break the while loop
    k = cv2.waitKey(1)
    if k == ord('q'):
        break

# release your camera device and close the OpenCV windows
camera.release()
cv2.destroyAllWindows()

Run the demo

Install the OpenCV:

pip install -r requirements.txt

Please save the Python as opencv_capture_camera_video.py and run it in console：

python opencv_capture_camera_video.py

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使用OpenCV捕捉电脑摄像头视频

项目需求

• 运行程序会打开电脑摄像头，并显示捕捉到的视频
• 按q键会退出程序

项目练习

• 安装OpenCV，需要使用pip install opencv-python将OpenCV安装到项目环境中
• while循环
• if条件判断
• OpenCV窗口按键

项目参考代码

import cv2

# 打开电脑摄像头
# 默认摄像头编号为0，如果你的电脑默认摄像头编程不为0，请使用其他数字
camera = cv2.VideoCapture(0)

# 重复去读取摄像头捕捉到的视频
while True:
    success, img = camera.read()
    # 如果捕捉成功，将捕捉到的视频显示在一个"Video"窗口中
    if success:
        cv2.imshow('Video', img)
    # 当在Video窗口上按下k键退出程序
    k = cv2.waitKey(1)
    if k == ord('q'):
        break

# 释放摄像头并关闭OpenCV打开的窗口
camera.release()
cv2.destroyAllWindows()

测试运行

Install OpenCV:

pip install -r requirements.txt

保存代码为opencv_capture_camera_video.py并运行：

python opencv_capture_camera_video.py