def test_make_lut():
"""Should create valid lookup table."""
cm = {1: [100, 100, 100, 255], 2: [255, 255, 255, 255]}
lut = colormap.make_lut(cm)
assert len(lut) == 256
assert lut[0].tolist() == [0, 0, 0, 0]
assert lut[1].tolist() == [100, 100, 100, 255]
assert lut[4].tolist() == [0, 0, 0, 0]
def main(out_dir, img_height):
"""Create PNG images from rio-tiler colormaps
"""
out_dir = Path(out_dir)
out_dir.mkdir(exist_ok=True, parents=True)
for cmap_name in cmap_list:
arr = make_lut(get_colormap(cmap_name))
# Add axis
arr = arr[np.newaxis, ...]
# Make n pixels high
arr = np.vstack([arr] * img_height)
# Write to image
imageio.imwrite(out_dir / f'{cmap_name}.png', arr)
def make_colormap(name):
"""Use rio-tiler colormap to create matplotlib colormap
"""
colormap = make_lut(cmap.get(name))
# rescale to 0-1
return ListedColormap(colormap / 255, name=name)