Artifact removal for GLS map makers by means of post-processing.

The quality of astrophysical images produced by means of the Generalised Least Square (GLS) approach may be degraded by the presence of artificial structures, obviously not present in the sky. This problem affects in different degrees all images produced by the instruments onboard the European Space Agency (ESA) Herschel satellite. In this paper we analyse these artifacts and introduce a method to remove them.