Python - 更改像素值

Question

I have used this code to change the pixel value of image,

im=Image.open("image.jpg")
pix=im.load()
pix[50,50]=(70,70,70)

it is work well with me, but when I use a png image everything is okay and the changes are saved to the image, but when I use a JPG image the changes are not saved to the image. Is there something missing in the code, do I need to save the changes , and how would I do ??

Answer 1

Try with:

im.putpixel((50,50), (70, 70, 70))

or you can also do:

import numpy as np
from PIL import Image

# pix has 4 channels for png and 3 for jpg
pix = np.array(im)

pix[50, 50, 0] = 70      # 0 accesses the first channel
pix[50, 50, 1] = 70      # 1 accesses the second channel
pix[50, 50, 2] = 70      # 2 accesses the third channel

Image.fromarray(pix).save('new_img.jpg')

Answer 2

Save the image with the previous file name. That worked for me well

im=Image.open("image.jpg")
pix=im.load()
pix[50,50]=(70,70,70)
img.save("image.jpg")