Invoking Napari from Julia Language 1.3.1

napari.jl

"""
napari.jl

Test using PyCall.jl to invoke Napari ( http://github.com/napari ) from
the Julia language ( https://julialang.org/ ) 1.3.1

Mark Kittisopikul
January 29th, 2020
"""

using PyCall

pygui_start(:qt5)
# needed to kickstart Qt5 for some reason
qapp_obj = pyimport("qtpy.QtWidgets").QApplication([""])
napari = pyimport("napari")

skimagedata = pyimport("skimage.data")
astronaut = skimagedata.astronaut();
# Modified 2020/09/14 to add name keyword argument
# https://github.com/napari/napari/issues/1630
napari.view_image(astronaut, name="astronaut")

using Images, TestImages

hela = testimage("hela-cells.tif");
hela = imadjustintensity(hela);
hela = channelview(hela);
hela = PermutedDimsArray(hela,(2,3,1));
#napari cannot handle UInt16 ?? Maybe QT issue
#hela = reinterpret(UInt16,hela);
napari.view_image(collect(Float32.(hela)))

mandrill = testimage("mandrill.tif");
mandrill = channelview(mandrill);
mandrill = reinterpret(UInt8,mandrill);
mandrill = PermutedDimsArray(mandrill,(2,3,1));
napari.view_image(collect(mandrill));

if !isinteractive()
    qapp_obj.exec()
end

A Napari.jl package would still depend on PyCall.jl to do the heavy lifting. The other route that could be considered would be using https://zeromq.org/

Some of the issues are Napari bugs due to unexpected input from Julia. Some are PyCall issues. The intent of a Napari.jl package would be to try to save the user from some of those gotchas by normalizing the data.

The Gtk threading issues are unfortunate. There might be a way to pin tasks to threads though, which might resolve some of the issues:
https://julialang.zulipchat.com/#narrow/stream/225542-helpdesk/topic/confused.20by.20how.20threads.20are.20scheduled/near/217623767
JuliaLang/julia#34267 (comment)

I have motivation to roll out a v0.0.1 Napari.jl package this week due to the I2K conference.

Yeah, I guess PyCall.jl is still the best option atm.

If I can help you, just reach out. I'm not experienced in shipping PyCall based packages but maybe I can support adding edge cases which crash.

It would be also cool if it's possible to run Napari in different threads or to prevent that they crash the whole Pluto session.

I haven't forgotten about this. Just a bit busy at the moment.

If you are interested in a full blown Julia package, check out the early preview of Napari.jl: https://github.com/mkitti/Napari.jl