Multiple Output Channel Restoration Methods

In order to address the problem of point-source photometry in restored images Lucy (1994) proposed and tested a two channel ``photometric restoration method''. In the initial concept the output restored image was divided into two channels. One contained point-sources which were represented as $\delta$-functions at user specified positions. The other channel was constrained to be smooth by an additional entropy term and was used to model the background intensity distribution due to both objects in the field with extended emission and any other sources of background. This method was implemented and made available as a code known as plucy in the STSDAS `contrib' package. This is described in Hook & Lucy 1995. This code has been successfully used for several astronomical projects. See for example Close et al. (1998) or Brandl et al. (1996) where the method is used to process adaptive optics images. Hook et al. (1994) show how it can be used to reveal a QSO host galaxy underlying a very bright point source.