Assuming the halo was not introduced when the image was dropped out of the green screen, this seems like something that would be handled via the trapping options in the DFE.
We are getting a digital halo effect around a cut out photo dropped out of a green screen in Photoshop. The PSD SRGB photo is then placed in InDesign on top of a spot color radio gradient that was created in InDesign. We then sent a live PDF to the Fre Flow Core which is interpreted by the Adobe Print Engine. Any suggestions on how to eliminate this issue?