python 2.7 - How to convert wand image object to open cv image (numpy array)

Question

I have imported wand using the following code

from wand.image import Image as WandImage
from wand.color import Color
with WandImage(filename=source_file, resolution=(RESOLUTION,RESOLUTION)) as img:
    img.background_color = Color('white')
    img.format        = 'tif'
    img.alpha_channel = False

How can i convert img object to open cv (cv2) image object in python?

Answer 1

You would simply write to a byte-array buffer, and pass to cv2.imdecode.

from wand.image import Image as WandImage
from wand.color import Color
import numpy
import cv2

RESOLUTION=72
source_file='rose:'
img_buffer=None

with WandImage(filename=source_file, resolution=(RESOLUTION,RESOLUTION)) as img:
    img.background_color = Color('white')
    img.format        = 'tif'
    img.alpha_channel = False
    # Fill image buffer with numpy array from blob
    img_buffer=numpy.asarray(bytearray(img.make_blob()), dtype=numpy.uint8)

if img_buffer is not None:
    retval = cv2.imdecode(img_buffer, cv2.IMREAD_UNCHANGED)