使用 Pillow 降低图像的亮度

Question

I'm using Pillow for a project, and I really want to create an effect like in the following Image, look:

In this picture, you see like the background Image is opaque, I don't know if that's the word I need to use. What I want to do is that the text is brighter than the background Image, this is a nice effect.

Can I duplicate this effect in Pillow? and if so, what would be the function? Thank you a lot. I know this is a broad question, but since I don't know how to even ask the question the proper way, I will accept any suggestion that will lead me to the right path.

PS. I found this picture at: http://qz.com/402739/the-best-idioms-from-around-the-world-ranked/

Answer 1

Based on the comment of @martineau

from PIL import Image

im = Image.open('image-to-modify.jpg')

source = im.split()

R, G, B = 0, 1, 2
constant = 1.5 # constant by which each pixel is divided

Red = source[R].point(lambda i: i/constant)
Green = source[G].point(lambda i: i/constant)
Blue = source[B].point(lambda i: i/constant)

im = Image.merge(im.mode, (Red, Green, Blue))

im.save('modified-image.jpeg', 'JPEG', quality=100)

Answer 2

As stated in the docs you can use Pillow's ImageEnhance module for lowering or increasing the brightness of an image.

Minimal Working Example (MWE):

from PIL import Image, ImageEnhance

img = Image.open("image.jpg")
enhancer = ImageEnhance.Brightness(img)
# to reduce brightness by 50%, use factor 0.5
img = enhancer.enhance(0.5)

img.show()
img.save("image_darker.jpg")

So to get the text of the image brighter than the background image, first apply the effect to the image, then add the text.