add background to icon with its dominant color

dominant_color.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# vi: set ft=python :
'''
usage: dominant.py --filename=<path> [--order=<order>] [--npoints=<value>]

options:
    -f path, --filename=path       Name of the icon
    -o value, --order=value        Order of the super ellise [default: 4]
    -n points, --npoints=npoints   Number of points that render the background [default: 50]
'''

import docopt
import os
import sys
from math import pi, cos, sin, pow, fabs, copysign
from PIL import Image, ImageDraw
import svgwrite


def get_dominant_color(image, numcolors=100, resize=150):
    image = image.resize((resize, resize))
    im = image.convert('P', palette=Image.ADAPTIVE, colors=numcolors)
    if im.mode == 'P':
        im.putalpha(0)

    colors = im.getcolors(resize*resize)
    col = sorted(colors, key=lambda x: x[0])
    return col[-3][1]


def signed_power(x,y):
        """Returns x to the power y, but preserves the sign of x
           This allows us to plot all four quadrants with a single loop and
           no additional sign logic"""
        return copysign(pow(fabs(x),y) ,x)


def draw_squircle(size, order=4, npoints=50):
    power = 2.0 / order
    theta = pi * 2.0 / npoints
    cx = cy = size / 2.0;
    radiusx = radiusy = size / 2.0

    points = []
    for i in range(npoints):
        x = cx + radiusx * signed_power(cos(i*theta), power)
        y = cy + radiusy * signed_power(sin(i*theta), power)
        points.append((x,y))

    return points

def get_img_squircle(points, size, fillcolor, linecolor):
    im = Image.new('RGBA', size, 4*(0))
    draw = ImageDraw.Draw(im)
    draw.polygon(points, fill=fillcolor, outline=linecolor)
    return im


#def get_svg_squircle(points, fillcolor, linecol, outfile):
#    fillcol = "rgb(%d,%d,%fill" % fillcolor[:3]
#    linecol = "rgb(%d,%d,%d)" % linecolor[:3]
#    svg_doc = svgwrite.Drawing(filename=outfile)
#    svgdoc.add(svgdoc.polygon(points=points, stroke_width="1", fill=fillcol, stroke=linecol))
#    return svgdoc


def overlay(icon, background, filename):
    """Overlay icon with background"""
    # background = background.resize((icon.width, icon.height))

    print('background = %d x %d' % (background.width, background.height))
    print('image = %d x %d, %s' % (icon.width, icon.height, icon.mode))

    overlay = Image.composite(icon, background, background)
    overlay.show()

# Command Line Handling

if __name__ == '__main__' :
    args = docopt.docopt(__doc__)
    print(args)

    icon_name = args['--filename']
    icon = Image.open(icon_name).convert('RGBA')
    color = get_dominant_color(icon)

    order = float(args['--order'])
    npoints = int(args['--npoints'])
    size = icon.size
    points = draw_squircle(size[0], npoints, npoints=npoints)
    background = get_img_squircle(points, size, color, color)

    # save_img_squircle(points, color, color, 'background.png')
    overlay(icon, background, 'new_' + icon_name)