How do I infoWindow a MapImageLayer?

[SteveCole]

This has me stumped. I want to access the pixel values of a mapImageLayer and provide the user with an infoWindow where they clicked to return some related information. QueryTask and IdentifyTask only take URLs from REST services so how (can) one do an infoWindow with mapImageLayers?

Thanks-
Steve

[SteveCole]

Bump. Anyone? Bueller?

If it's not supported within the API, can this be done with a GP service? I noticed that in ArcToolbox there's a "Get Cell Value" tool under Data Management->Raster->Raster Properties. I wonder if that tool can be published as a GP service and then used with my mapImageLayer..