import numpy as np
from PIL import Image as PILImage


channel = int(np.ceil(len(img_msg.data)/(img_msg.height * img_msg.width)))
im = np.ndarray(shape=(img_msg.height, img_msg.width, channel),
                dtype=np.uint8, buffer=img_msg.data)
pim = PILImage.fromarray(im)

pim.show()