fd = open('foo.jpg')
img_str = fd.read()
fd.close()
nparr = np.fromstring(img_str, np.uint8)
img_np = cv2.imdecode(nparr, cv2.CV_LOAD_IMAGE_COLOR)
img_ipl = cv.CreateImageHeader((img_np.shape[1], img_np.shape[0]), cv.
    IPL_DEPTH_8U, 3)
cv.SetData(img_ipl, img_np.tostring(), img_np.dtype.itemsize * 3 * img_np.
    shape[1])
print(type(img_str))
print(type(img_np))
print(type(img_ipl))
Python OpenCV load image from byte string