Matplotlib RGB & OpenCV BGR
import matplotlib.pyplot as plt
import numpy as np
import cv2
img = np.array([
[[255, 0, 0], [0, 255, 0], [0, 0, 255]],
[[255, 255, 0], [255, 0, 255], [0, 255, 255]],
[[255, 255, 255], [128, 128, 128], [0, 0, 0]],
], dtype=np.uint8)
plt.imsave(‘img_pyplot.png’, img)
cv2.imwrite(‘img_cv2.jpg’, img)
