  Scanamorphos is public software initially developed to post-process scan
observations performed with the Herschel photometer arrays. This
post-processing mainly consists in subtracting the total low-frequency noise
(both its thermal and non-thermal components), masking cosmic ray hits, and
projecting the data onto a map. Building upon the results obtained for
P-ArT\'eMiS (the prototype of ArT\'eMiS), Herschel and then NIKA2 (a resident
camera of the IRAM 30-m telescope operating at 1.25 and 2 mm), it has now been
tailored to the ArT\'eMiS camera, an ESO and OSO P.I. instrument installed at
the APEX 12-m telescope, demonstrating our initial claim that the software
principles were directly transposable to scan observations made with other
instruments, including from the ground, provided they entail sufficient
redundancy. This document explains how the algorithm was modified to cope with
the specificities of ArT\'eMiS observations and with the atmospheric emission
at 350 and 450 $\mu$m, far dominating the instrumental drifts that were the
only low-frequency noise component in Herschel data. Like in the original
software, this was accomplished without assuming any noise model and without
applying any Fourier-space filtering, by exploiting the redundancy built in the
observations - taking advantage of the fact that each portion of the sky is
sampled at multiple times by multiple bolometers. It remains an interactive
software in the sense that the user is allowed to optionally visualize and
control results at each intermediate step, but the processing is fully
automated. It has been grafted onto the ArT\'eMiS pipeline, in charge of the
formatting, calibration and projection of the data, that is described
elsewhere.
