Hi Don, an update:
I changed my code from
ImageRGBDisplayable.setData( myField );
ImageRGBDisplayable.loadData( myField );
and now I DO see my image. I got the idea from the idv class ImageControl, which maintains an ImageRGBDisplayable instance and
calls loadData on it.
Alas the original color scheme does not seem to have been preserved, as it was in the case of the VisAD code, i.e. using just
Visad objects, none from IDV. How do I get my ImageRGBDisplayable to preserve my source color palette?