complex_paint.py

#!/usr/bin/env python3

import numpy as np
from PIL import Image
import matplotlib.pyplot as plt
import cplot

#fname, paint = './Seurat_afternoon.jpg', 'Georges Seurat'
fname, paint = './munch.jpg', 'Munch scream'
#fname, paint = './Gaugin.jpg', 'Paul Gaugin'
#fname, paint = './van_gogh.jpg', 'Vincent van Gogh'
#fname, paint = './mondriaan.jpg', 'Piet Mondrian'
image = Image.open(fname)

width, height = image.size
print('Original image h, w', width, height, 'ratio', width/height)
scale = 1
image = image.resize((width//scale, height//scale))
width, height = image.size
print('Rescaled 1/%i image h,w' % scale, width, height, 'ratio', width/height)
im = np.array(image)
print('Mesh shape', im.shape)
# plt.imshow(im)
# plt.show()

im = np.array(image.rotate(-90, expand=True))

nx, ny = im.shape[0], im.shape[1]
imlist = np.array([[*im[i,j]/255,1] for i in range(nx) for j in range(ny)])
print('Point-wise RGB shape', imlist.shape)

ratio = ny/nx
# x0, x1, y0, y1 = 0,1, 0*ratio,1*ratio
x0, x1, y0, y1 = -2, 2, -2*ratio, 2*ratio
p = np.array([i + 1.j*j for i in np.linspace(x0,x1,nx) for j in np.linspace(y0,y1,ny)], dtype=np.complex_)
print('Points', p.shape)
# plt.scatter(p.real, p.imag, c=imlist, marker='.')
# plt.gca().set_aspect('equal')
# plt.show()

f_list = [
    lambda z: np.cos(z-1),
    lambda z: (2*z+1)/(5*z-5/2),
    lambda z: z**(4/5)-1,
    lambda z: z**(5/4)-1,
    lambda z: np.log(z+1),
    lambda z: (z+1)**(1/6)
]
label_list = [
    r'$\cos(z-1)$',
    r'$\frac{2 z + 1}{5 z-5/2}$',
    r'$z^{4/5}-1$',
    r'$z^{5/4}-1$',
    r'$\log(z+1)$',
    r'$(z+1)^{1/6}$'
]

ind = 5
f, label = f_list[ind], label_list[ind]

fig, (ax_orig, ax_map) = plt.subplots(1,2, dpi=150)
fig.suptitle(r'%s via %s' % (paint, label))
ax_orig.set_aspect('equal')
ax_map.set_aspect('equal')

ax_orig.scatter(p.real, p.imag, c=imlist, marker='.')
plt.sca(ax_orig)
plt = cplot.plot_contours(f,
                          (x0, x1, 400),
                          (y0, y1, 400),
                         )
ax_orig.set_xlim([x0, x1])
ax_orig.set_ylim([y0, y1])
fofp = f(p)
ax_map.scatter(fofp.real, fofp.imag, c=imlist, marker='.')
# ax_map.set_xlim([-1, 2])
# ax_map.set_ylim([-3, 3])

# side = 0.9
# ax_map.set_xlim([-side, side])
# ax_map.set_ylim([-side, side])

# Mobieus transform (ind 1?)
#ax_map.set_xlim([-0.1, 1])
#ax_map.set_ylim([-0.6, 0.6])

ax_orig.axis('off')
ax_map.axis('off')
plt.tight_layout()
plt.show()