import numpy as np
import holoviews as hv
from holoviews import opts
hv.extension('plotly')

hv.RGB.load_image('../assets/penguins.png')

x,y = np.mgrid[-50:51, -50:51] * 0.1

r = 0.5*np.sin(np.pi  +3*x**2+y**2)+0.5
g = 0.5*np.sin(x**2+2*y**2)+0.5
b = 0.5*np.sin(np.pi/2+x**2+y**2)+0.5

hv.RGB(np.dstack([r,g,b]))

opts.defaults(opts.Image(cmap='gray'))

hv.Image(r,label="R") + hv.Image(g,label="G") + hv.Image(b,label="B")

mask = 0.5*np.sin(0.2*(x**2+y**2))+0.5
rgba = hv.RGB(np.dstack([r,g,b,mask]))

bg = hv.Image(0.5*np.cos(x*3)+0.5, label="Background") * hv.VLine(x=0,label="Background")
overlay = (bg*rgba).relabel("RGBA Overlay")
bg + hv.Image(mask,label="Mask") + overlay

hv.Overlay([hv.RGB.load_image('../assets/penguins.png', bounds=(2*i,2*i,3*i,3*i))
            for i in range(1,8)])