Question

Python how to get a list of color that used in one image

I use PIL, and I want to have a dictionary of colors that are used in this image, including color(key) and number of pixel points it used.

How to do that?

Answer 1

I have used something like the following a few times to analyze graphs:

>>> from PIL import Image
>>> im = Image.open('polar-bear-cub.jpg')
>>> from collections import defaultdict
>>> by_color = defaultdict(int)
>>> for pixel in im.getdata():
...     by_color[pixel] += 1
>>> by_color
defaultdict(<type 'int'>, {(11, 24, 41): 8, (53, 52, 58): 8, (142, 147, 117): 1, (121, 111, 119): 1, (234, 228, 216): 4

Ie, there are 8 pixels with rbg value (11, 24, 41), and so on.