Export to OMERO big image

[will-moore]

See https://forum.image.sc/t/omero-figure-fails-when-exporting-as-a-new-omero-image/43498/4

Currently, an A4 page at 300 dpi is about 2500 pixels width/height?
Bigger pages will become Big tiled images when exported to new images in OMERO.

Need to use setTile() logic to create a Big Image from a bigger PIL Image.
There will also be a limit on how big a figure can be exported as TIFF or OMERO, if we can't hold it all in memory in PIL, but that might be quite large.

[imagesc-bot]

This issue has been mentioned on Image.sc Forum. There might be relevant details there:

https://forum.image.sc/t/omero-figure-fails-when-exporting-as-a-new-omero-image/43498/5