missing alpha in gv.load_tiff

[oarcher]

it seems that the alpha channel is missing when loading a tiff file with gv.load_tiff

!wget https://cerweb.ifremer.fr/oarcher/tmp/test_alpha.tiff
import geoviews as gv
gv.extension('bokeh')

gv.tile_sources.Wikipedia * gv.load_tiff('test_alpha.tiff')

That's because in

geoviews/geoviews/util.py

Line 731 in 8d7669f

vdims = el.vdims[:bands]

el.vdims is [Dimension('R'), Dimension('G'), Dimension('B')] (A dimension is missing)

A partial workaround is to replace with

vdims = list('RGBA')[:bands]

But perhaps that gv.RGB.vdims should also return Dimension('A') ?

geoviews 1.9.5.post4+g8d7669f.dirty installed from master branch.