Python枕头改变像素的RGB值？

Question

I'm trying to change the pixels on my picture to darker green than I have already made it, I am trying to add + rgb(0,50,0) to it but I can't seem to be able to do so, could you help? I have put my code in below, and freljord2.png is now just a full green image using getcolor(green, "RGBA")

im = Image.open('freljord2.png')
#one_pixel = im.getpixel((0, 0))
#one_pixel[1] = 0;
#im.save('freljord3.png')


(0, 0, 0, 0)
for x in range(0):
for y in range(0):
    im.putpixel((x, y), (210, 210, 210))
for x in range(560):
    for y in range(557):
    print("hi")
    hello = ImageColor.get(00B200)
    im.putpixel((x, y), )
im.getpixel((0, 0))
(210, 210, 210, 255)
im.getpixel((0, 50))
(169, 169, 169, 255)
im.save('freljord2.png')

Answer 1

You mention that you want to make your image more dark green, but if you add 50 to each pixel value of an image, you only make it brighter (and greener). What you want to do is to place a green transparent overlay over your existing image. You should create a new image for that with the same size as your original with the color you want to add, and an alpha value, which indicates how transparent it is. Next, you need to paste that image over your original image using a mask.

The following code example should do the trick. The result is shown below. You can play around a little bit with the values to tailor to your needs.

'''
Created on Oct 23, 2016

@author: physicalattraction
'''

import os.path
from PIL import Image


def get_img_dir() -> str:
    '''
    Return the full path to the image directory

    :return: string
    '''
    pkg_dir = os.path.dirname(__file__)
    img_dir = os.path.join(pkg_dir, '..', '..', 'img')
    return img_dir


def open_img(img_name: str) -> Image:
    '''
    Open the given file form the image directory

    :param img_name: Name including extension of the image
    :return: Image object
    '''
    img_dir = get_img_dir()
    full_img_path = os.path.join(img_dir, img_name)
    return Image.open(full_img_path)


def save_img(img: Image, img_name: str):
    '''
    Save the given image to the image directory

    :param img: Image object
    :param img_name: Name including the extension of the image
    '''
    img_dir = get_img_dir()
    full_img_path = os.path.join(img_dir, img_name)
    img.save(full_img_path)


def overlay(img: Image, overlay_color: tuple):
    '''
    Place an overlay over an existing image

    :param img: Image opened with PIL.Image
    :param overlay_color: four-tuple with color to add to your image
    '''
    assert len(overlay_color) == 4, 'Overlay color shall be a 4-tuple'

    img_overlay = Image.new(size=img.size, color=overlay_color, mode='RGBA')
    img.paste(img_overlay, None, mask=img_overlay)

    color_string = '_'.join([str(c) for c in overlay_color])
    filename = 'amsterdam_{color}.jpg'.format(color=color_string)
    save_img(img, filename)


if __name__ == '__main__':
    ams = open_img('amsterdam.jpg')
    green = (0, 50, 0, 128)
    overlay(ams, green)

Original image:

Darker green image: