如何使用Numpy/PIL对图像进行白平衡

import numpy as np
from PIL import Image

image = Image.open('image.jpg')

image_array = np.array(image)

avg_brightness = np.average(image_array)

red_gain = avg_brightness / np.average(image_array[:, :, 0])
green_gain = avg_brightness / np.average(image_array[:, :, 1])
blue_gain = avg_brightness / np.average(image_array[:, :, 2])

image_array[:, :, 0] *= red_gain
image_array[:, :, 1] *= green_gain
image_array[:, :, 2] *= blue_gain

balanced_image = Image.fromarray(np.uint8(image_array))

balanced_image.save('balanced_image.jpg')