Count colors in an image

palette.py

#!/usr/bin/env python3

from collections import Counter
import numpy
from PIL import Image
from webcolors import css3_hex_to_names, hex_to_rgb
from urllib.request import urlopen
import sys
import time
import matplotlib.pylab as plb
import matplotlib.pyplot as plt

plt.switch_backend('cairo')
plb.switch_backend('cairo')

BASEWIDTH = 50


def plot_colorpalette_result(name, element_labels, element_fracs, element_color_names):
    plb.figure(1, figsize=(10, 10))
    labels = element_labels
    fracs = element_fracs
    plb.pie(fracs, labels=labels, shadow=True, startangle=90, colors=element_color_names)
    plb.title(name, bbox={'facecolor': '1', 'pad': 5})
    filename = '{0}.png'.format(time.strftime('%y%m%d%H%M%s'))
    plb.savefig(filename)


def color_palette(path):
    mc = _get_image_palette(urlopen(path)).most_common()
    elements = {x[1]: x[0] for x in mc}
    element_total = sum(elements.keys())
    elements = {int(k / element_total * 100): v for k, v in elements.items()
                if k > element_total / 20}
    element_labels = ['{0},{1}%'.format(v, k) for k, v in elements.items()]
    plot_colorpalette_result(path, element_labels, list(elements.keys()),
                             list(elements.values()))


def _resize_image(image):
    width, height = image.size
    if width > BASEWIDTH:
        wpercent = (BASEWIDTH / float(image.size[0]))
        hsize = int((float(image.size[1]) * float(wpercent)))
        return image.resize((BASEWIDTH, hsize), Image.ANTIALIAS)
    return image


def _get_image_palette(path):
    image = _resize_image(Image.open(path))
    data = numpy.asarray(image).reshape(numpy.prod(image.size), 3)
    counter = Counter(tuple(map(tuple, data)))
    color_names = [_get_closest_color(element) for element
                   in counter.elements()]
    return Counter(color_names)


def _get_closest_color(c):
    m = {((v[0] - c[0]) ** 2 + (v[1] - c[1]) ** 2 + (v[2] - c[2]) ** 2): k for
         k, v in
         {v: hex_to_rgb(k) for k, v in css3_hex_to_names.items()}.items()}
    return m[min(m.keys())]


if __name__ == '__main__':
    try:
        color_palette(sys.argv[1])
    except IndexError:
        print('Rerun with url as first arg', file=sys.stderr)