Colab环境中没有本地视频设备;它运行在云中的某个地方。我们需要的是浏览器中的一些JavaScript，以便访问用户附近的摄像头。Colab提供了代码片段示例，其中一个是用于视频捕获的，我在下面介绍了这些示例。
先运行此单元格。

from IPython.display import display, Javascript
from google.colab.output import eval_js
from base64 import b64decode

def take_photo(filename='photo.jpg', quality=0.8):
js = Javascript('''
  async function takePhoto(quality) {
    const div = document.createElement('div');
    const capture = document.createElement('button');
    capture.textContent = 'Capture';
    div.appendChild(capture);

    const video = document.createElement('video');
    video.style.display = 'block';
    const stream = await navigator.mediaDevices.getUserMedia({video: true});

    document.body.appendChild(div);
    div.appendChild(video);
    video.srcObject = stream;
    await video.play();

    // Resize the output to fit the video element.
    google.colab.output.setIframeHeight(document.documentElement.scrollHeight, true);

    // Wait for Capture to be clicked.
    await new Promise((resolve) => capture.onclick = resolve);

    const canvas = document.createElement('canvas');
    canvas.width = video.videoWidth;
    canvas.height = video.videoHeight;
    canvas.getContext('2d').drawImage(video, 0, 0);
    stream.getVideoTracks()[0].stop();
    div.remove();
    return canvas.toDataURL('image/jpeg', quality);
  }
  ''')
display(js)
data = eval_js('takePhoto({})'.format(quality))
binary = b64decode(data.split(',')[1])
with open(filename, 'wb') as f:
  f.write(binary)
return filename

运行此单元时，您必须允许视频访问。

from IPython.display import Image
try:
  filename = take_photo()
  print('Saved to {}'.format(filename))

  # Show the image which was just taken.
  display(Image(filename))
except Exception as err:
  # Errors will be thrown if the user does not have a webcam or if they do not
  # grant the page permission to access it.
  print(str(err))