HST image restoration developments at the ST-ECF

When spherical aberration was found to be degrading the performance of the Hubble Space Telescope (HST), great interest in image restoration methods arose in the astronomical community. The Richardson-Lucy (RL) method became the preferred tool for restoring such data which typically has Poisson noise characteristics and a low signal-to-noise ratio. Subsequently, corrective optics were inserted into the telescope which is now operating close to the original specifications. However, generalized RL methods and some new techniques based on projections onto convex sets have proved useful both for the present HST data, which are often insufficiently sampled, and also for many other classes of astronomical images. The ST-ECF staff have worked extensively in this and related areas, and some of these developments and their application to real data are described. (C) 1995 John Wiley & Sons, Inc.