Python - 手动将 RGB 图片转换为灰度

Question

I want to convert an rgb image to 2d matrix in gray. How can I do this using loops and PIL? I don't want to use a canned function. How can I do that?

Answer 1

I manipulate a lot of images as NumPy arrays like so:

import numpy as np
from PIL import Image

# Load image
imgIn = Image.open(''c:/path/to/my/input/file.jpg'')
imgArray = np.array(imgIn)

#Do whatever manipulations to the image you need to, e.g.,
grayArray = np.mean(imgArray,axis=2)

#Save the final result
imgOut = Image.fromarray(grayArray)
imgOut.save('c:/path/to/my/output/file.jpg')