make squircles using pillow ♥

squircle.py

import sys
from PIL import Image
import numpy as np
import math


def squircle(size=(50,50), color="black", level=4):
	i = Image.new(mode = 'RGBA', size=size , color=color )
	l = level
	w, h = i.size
	r = w if w < h else h
	a = np.full((r, r), 255, 'u1')
	for x in range(r):
	  for y in range(r):
	    d = math.pow(x**l + y**l, 1/l) - r + 2
	    if d > 1:
	      a[y, x] = 0
	    elif d > 0:
	      a[y, x] = round((1 - d)*255)
	a = np.concatenate([np.array([a[:, 0]]).repeat(w - r, 0).T, a], 1)
	a = np.concatenate([np.array([a[0, :]]).repeat(h - r, 0), a])
	a = np.concatenate([np.concatenate([np.rot90(a, 2), a[:, ::-1]]), np.concatenate([a[::-1, :], a])], 1)
	m = Image.fromarray(a)
	m.thumbnail(i.size, Image.LANCZOS)
	i.putalpha(m)
	return i


if __name__ == "__main__":
	i = squircle()
	i.save("squircle.png")