ImageOverlay does not accept data uris as valid and treats them as file name instead

[Kirill888]

Describe the bug

Supplying a data URI as image parameter to ImageOverlay raise FileNotFound error.

To Reproduce

from folium.raster_layers import ImageOverlay
img_url = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg=="
ImageOverlay(img_url, bounds=[[0,0], [1,1]])

Expected behavior
Image url is passed into output as is.

Environment (please complete the following information):

• Browser firefox
• Jupyter Notebook or html files -- jupyter lab?
• Python version 3.8
• folium version 0.11.0
• branca version 0.3.1

Possible solutions

Problem is due to data scheme being absent from the allow list here:

folium/folium/utilities.py

Lines 22 to 23 in ae12f97

	_VALID_URLS = set(uses_relative + uses_netloc + uses_params)
	_VALID_URLS.discard('')

Patching it at run time solves the problem, i.e. this works as expected

import folium.utilities
folium.utilities._VALID_URLS.add('data')

from folium.raster_layers import ImageOverlay
img_url = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg=="
ImageOverlay(img_url, bounds=[[0,0], [1,1]])

[Conengmo]

Good find! Do you want to open a PR with your fix? Add in a test case to verify behavior?

[Kirill888]

Sure, will do, soonish