OpenCV numpy image -> JPEG memory buffer -> bytes and back

opencv_bytes.py

import cv2
import numpy as np
import sys

img = cv2.imread('1.jpg')
print(sys.getsizeof(img))
img_encoded = cv2.imencode('.jpg', img)[1]
print(sys.getsizeof(img_encoded))

img_bytes = img_encoded.tobytes()  # bytes class

print(sys.getsizeof(img_bytes))

# 'repair' image from byte array

nparr = np.frombuffer(img_bytes, np.byte)
img2 = cv2.imdecode(nparr, cv2.IMREAD_REDUCED_COLOR_8)

print(sys.getsizeof(img2))
cv2.imwrite('out.jpg', img2, [cv2.IMWRITE_JPEG_PROGRESSIVE])