Create some ImgLib2 ROIs and attach them to an IJ1 ImagePlus

mix-ij2-and-ij2-rois.groovy

#@ ConvertService convert
#@ ImagePlus imp

import bdv.util.BdvFunctions
import bdv.util.BdvOptions

import ij.gui.Overlay
import ij.gui.Roi

import net.imglib2.roi.Masks
import net.imglib2.roi.geom.GeomMasks
import net.imglib2.view.Views
import net.imglib2.util.Intervals

// Create some ImgLib2 ROIs.
rois = [
	GeomMasks.closedEllipsoid([5, 6] as double[], [7, 8] as double[]),
	GeomMasks.polygon2D([2, 3, 4, 5, 6, 1, 9, 9] as double[], [7, 5, 3, 4, 6, 1, 1, 9] as double[]) // TODO Fiji logo
]

// Lump them into a collection.
roiTree = new net.imagej.roi.DefaultROITree()
roiTree.addROIs(rois)

// Define a function to show ROIs with BDV.
def showROIs(roi) {
	rrari = Masks.toRealRandomAccessibleRealInterval(roi)
	println(rrari)
	
	ra = Views.raster(rrari)
	println(ra)
	
	bounds = Intervals.smallestContainingInterval(rrari)
	rai = Views.interval(ra, bounds)

	BdvFunctions.show(rai, "Awesome", new BdvOptions().is2D())
}

// Uncomment this to show the ImgLib2 ROIs with the BDV.
//showROIs(roiTree.children().get(1).data())

// Convert IJ2 -> IJ1.
overlay = convert.convert(roiTree, Overlay.class)
println(overlay)

// You could also convert them individually if you like things to be more complicated. :-)
//roi0 = convert.convert(rois[0], Roi.class)
//println(roi0)
//roi1 = convert.convert(rois[1], Roi.class)
//println(roi1)
//overlay = new Overlay()
//overlay.add(roi0)
//overlay.add(roi1)

imp.setOverlay(overlay)