def test_io():
# Ensure that to_planar and from_planar do the right thing to shape.
a = np.array([[[1, 2, 3, 4], [5, 6, 7, 8]]], dtype='f8')
assert a.shape == (1, 2, 4)
b = snowy.to_planar(a)
assert b.shape == (4, 1, 2)
c = snowy.from_planar(b)
assert np.array_equal(a, c)
# Ensure that to_planar creates a copy, not a view.
b[0, 0, 0] = 100
assert np.amax(a) == 8
# Ensure that from_planar creates a copy, not a view.
c[0, 0, 0] == 200
assert np.amax(b) == 100
# Ensure that extract_rgb does the right thing with shape and makes
# a copy rather than a view.
color = snowy.extract_rgb(a)
assert color.shape == (1, 2, 3)
color[0, 0, 0] = 100
assert np.amax(a) == 8
# Ensure that extract_alpha does the right thing with shape and
# makes a copy rather than a view.
alpha = snowy.extract_alpha(a)
assert alpha.shape == (1, 2, 1)
alpha[0, 0, 0] = 100
assert np.amax(a) == 8
# This next snippet doesn't test Snowy but shows how to make a view
# of the alpha plane.
alpha_view = a[:, :, 3]
assert alpha_view[0, 0] == 4
assert alpha_view[0, 1] == 8
alpha_view[0, 0] = 100
assert np.amax(a) == 100
source = snowy.resize(gibbons, height=200)
blurry = snowy.blur(source, radius=4.0)
diptych_filename = qualify('diptych.png')
snowy.export(snowy.hstack([source, blurry]), diptych_filename)
optimize(diptych_filename)
snowy.show(diptych_filename)
# Moving on to magnification...
parrot = snowy.load(qualify('parrot.png'))
scale = 6
nearest = snowy.resize(parrot, width=32*scale, filter=snowy.NEAREST)
mitchell = snowy.resize(parrot, height=26*scale)
diptych_filename = qualify('diptych-parrot.png')
parrot = snowy.hstack([nearest, mitchell])
parrot = snowy.extract_rgb(parrot)
snowy.export(parrot, diptych_filename)
optimize(diptych_filename)
snowy.show(diptych_filename)
# EXR cropping
sunset = snowy.load(qualify('small.exr'), False)
sunset = sunset[:100,:,:] / 50.0
cropped_filename = qualify('cropped-sunset.png')
snowy.export(sunset, cropped_filename)
optimize(cropped_filename)
snowy.show(cropped_filename)
# Alpha composition