From a developer's perspective, it's not obvious that ParamVolume is intended to be used for 2D images. It would be great to have a trivial parameter type called ParamImage that extended ParamVolume. The only difference would be that ParamImage is a ParamVolume with only 1 slice and 1 component. It would also be great if there was a ParamMovie, which is a ParamVolume with a time resolution. This would enable forthcoming visualization components to render the data as intended (i.e. as a 2D image or movie).

Since a 2-D image is just a 3-D image with one volume, then it seems =
that the existing infrastructure works, but perhaps with confusing =
names.... ParamImageData would have been more appropriate, but alas, not =
to be.=20

In terms of ParamMovie, this seems like it might make sense to support =
additional file formats and intended targets. I'm not sure if this =
should extend ParamVolume of if it should be a separate tree... I =
welcome the discussion on the targets and functionality.=20