Sure. It should be as difficult as
I = gmt("read -Ti file.tiff");
if `file.tif`` is an image, or
G = gmt("read -Tg file.tiff");
if the file is a grid. Now, since the I type is only either 1 or 3 layers, for multi-layer files I would have to go to the GMT manual (not GMT.jl) to see how tha is done.
But we have been (similar to) here before. See this thread