I am trying to create an API which takes an image URL as input and returns back a color palette in JSON format as output.
It should work something like this: http://lokeshdhakar.com/projects/color-thief/
But should be in Python. I have looked into PIL (Python Image Library) but didn't get what I want. Can someone point me in the right direction?
Input: Image URL Output: List of Colors as a palette import numpy as np import Image def palette(img): """ Return palette in descending order of frequency """ arr = np.asarray(img) palette, index = np.unique(asvoid(arr).ravel(), return_inverse=True) palette = palette.view(arr.dtype).reshape(-1, arr.shape[-1]) count = np.bincount(index) order = np.argsort(count) return palette[order[::-1]] def asvoid(arr): """View the array as dtype np.void (bytes) This collapses ND-arrays to 1D-arrays, so you can perform 1D operations on them. http://stackoverflow.com/a/16216866/190597 (Jaime) http://stackoverflow.com/a/16840350/190597 (Jaime) Warning: >>> asvoid([-0.]) == asvoid([0.]) array([False], dtype=bool) """ arr = np.ascontiguousarray(arr) return arr.view(np.dtype((np.void, arr.dtype.itemsize * arr.shape[-1]))) img = Image.open(FILENAME, 'r').convert('RGB') print(palette(img)) palette(img) returns a numpy array. Each row can be interpreted as a color:
[[255 255 255] [ 0 0 0] [254 254 254] ..., [213 213 167] [213 213 169] [199 131 43]] To get the top ten colors:
palette(img)[:10] 
p = palette(img) with shape (nbcolors, 4), you could use p[:,None,:] or p[:,np.newaxis,:], or p.reshape(-1, 1, 4) to obtain an array of shape (nbcolors, 1, 4). (reshape will automatically replace the minus 1 with the only reasonable choice for you).The color-thief library is also available in python: https://github.com/fengsp/color-thief-py
Example implementation :
pip install colorthief # -*- coding: utf-8 -*- import sys if sys.version_info < (3, 0): from urllib2 import urlopen else: from urllib.request import urlopen import io from colorthief import ColorThief fd = urlopen('http://lokeshdhakar.com/projects/color-thief/img/photo1.jpg') f = io.BytesIO(fd.read()) color_thief = ColorThief(f) print(color_thief.get_color(quality=1)) print(color_thief.get_palette(quality=1)) 
I have looked into PIL (Python Image Library) but didn't get what I want- care to elaborate?