Wrapped holiday gift for Liana

liana_wrapped.py

import PIL
import numpy as np
from matplotlib.colors import LinearSegmentedColormap

# screenshot of Google Sheet with "Liana" written in 72 pt Pacifico font
text_img = PIL.Image.open("liana_text.png")
text_rgba = np.array(text_img)
text_gray = 1 - np.sum(text_rgba[..., :3], axis=-1) / (255 * 3)

y = np.linspace(0, 1, text_gray.shape[0])
x = np.linspace(0, 1, text_gray.shape[1])
z = np.outer(y, x)

wrapped = ((z * 10 - text_gray) % 2) / 2

cmy = LinearSegmentedColormap('cmy', {
    'red':   ((0.000, 0.0, 0.0),
              (0.333, 1.0, 1.0),
              (0.666, 1.0, 1.0),
              (1.000, 0.0, 0.0)),

    'green': ((0.000, 1.0, 1.0),
              (0.333, 0.0, 0.0),
              (0.666, 1.0, 1.0),
              (1.000, 1.0, 1.0)),

    'blue':  ((0.000, 1.0, 1.0),
              (0.333, 1.0, 1.0),
              (0.666, 0.0, 0.0),
              (1.000, 1.0, 1.0))
})
wrapped_colored = np.asarray(cmy(wrapped) * 255, dtype="uint8")

img_out = PIL.Image.fromarray(wrapped_colored)
img_out.save("liana_phase.png")