pythonopencvimage-processingscikit-imagemahotas

How can I read an image from an Internet URL in Python cv2, scikit image and mahotas?


How can I read an image from an Internet URL in Python cv2?

This Stack Overflow answer,

import cv2.cv as cv
import urllib2
from cStringIO import StringIO
import PIL.Image as pil
url="some_url"

img_file = urllib2.urlopen(url)
im = StringIO(img_file.read())

is not good because Python reported to me:

TypeError: object.__new__(cStringIO.StringI) is not safe, use cStringIO.StringI.__new__

Solution

  • Since a cv2 image is not a string (save a Unicode one, yucc), but a NumPy array, - use cv2 and NumPy to achieve it:

    import cv2
    import urllib
    import numpy as np
    
    req = urllib.urlopen('http://answers.opencv.org/upfiles/logo_2.png')
    arr = np.asarray(bytearray(req.read()), dtype=np.uint8)
    img = cv2.imdecode(arr, -1) # 'Load it as it is'
    
    cv2.imshow('lalala', img)
    if cv2.waitKey() & 0xff == 27: quit()