Generated moving checkered flag

flag.py

import numpy as np
import matplotlib.pyplot as plt
from skimage.transform import PiecewiseAffineTransform, warp, resize
from skimage import data
from PIL import Image, ImageDraw
import numpy as np
import scipy.misc as misc

image = Image.new("RGBA", (512, 512))
draw = ImageDraw.Draw(image)
sqSize = 128
halfSqSize = sqSize/2
draw.rectangle([0,0,image.size[0],image.size[1]], fill=(0,0,0,255))
for x in range(0, 512, sqSize):
	for y in range(0, 512, sqSize):
		draw.rectangle([x,y,x+halfSqSize,y+halfSqSize], fill=(255,255,255,255))
		draw.rectangle([x+halfSqSize,y+halfSqSize,x+sqSize,y+sqSize], fill=(255,255,255,255))
del draw
image = np.array(image)
rows, cols = image.shape[0], image.shape[1]

src_cols = np.linspace(0, cols, 20)
src_rows = np.linspace(0, rows, 10)
src_rows, src_cols = np.meshgrid(src_rows, src_cols)
src = np.dstack([src_cols.flat, src_rows.flat])[0]

# add sinusoidal oscillation to row coordinates
for i in range(10):
	print i
	step = 2.0 * i / np.pi
	dst_rows = src[:, 1] - np.sin(np.linspace(0, 3 * np.pi, src.shape[0])+step) * 30
	dst_cols = src[:, 0]
	dst_rows *= 1.5
	dst_rows -= 1.5 * 50
	dst = np.vstack([dst_cols, dst_rows]).T


	tform = PiecewiseAffineTransform()
	tform.estimate(src, dst)

	out_rows = image.shape[0] - 1.5 * 50
	out_cols = cols
	out = warp(image, tform, output_shape=(out_rows, out_cols))
	misc.imsave("flag{0}.png".format(i), out)
	#outResize = resize(out, (64, 64))
	#misc.imsave("flag{0}.png".format(i), outResize)