如何在Python3中使用opencv从文件缓冲区读取文件

Question

我正在尝试使用此库。特别是以下3行：

    image_stream = io.BytesIO(image_bytes)
    frame = cv2.imread(image_stream)

我有一个例外：

Traceback (most recent call last):
  File "/home/a/Pictures/pycharm-community-2018.3.2/helpers/pydev/pydevd.py", line 1741, in <module>
    main()
  File "/home/a/Pictures/pycharm-community-2018.3.2/helpers/pydev/pydevd.py", line 1735, in main
    globals = debugger.run(setup['file'], None, None, is_module)
  File "/home/a/Pictures/pycharm-community-2018.3.2/helpers/pydev/pydevd.py", line 1135, in run
    pydev_imports.execfile(file, globals, locals)  # execute the script
  File "/home/a/Pictures/pycharm-community-2018.3.2/helpers/pydev/_pydev_imps/_pydev_execfile.py", line 18, in execfile
    exec(compile(contents+"\n", file, 'exec'), glob, loc)
  File "/home/a/Documents/wiker/main.py", line 13, in <module>
    if __name__ == '__main__': main()
  File "/home/a/Documents/wiker/main.py", line 10, in main
    article['video'] = video.make_video_from_article(article)
  File "/home/a/Documents/wiker/video.py", line 15, in make_video_from_article
    frame = cv2.imread(image_stream)
TypeError: bad argument type for built-in operation

但是它适用于真实文件。可以在这里解决的问题。

Answer 1

这里是一个解决方案：

import io, requests, cv2, numpy as np

url = "https://images.pexels.com/photos/236047/pexels-photo-236047.jpeg"
img_stream = io.BytesIO(requests.get(url).content)
img = cv2.imdecode(np.fromstring(img_stream.read(), np.uint8), 1)

cv2.imshow("img", img)
cv2.waitKey(0)