Several different implementations of the Retinex model have derived from the original Land and McCann paper. This paper aims at presenting two of them: the Land Designator and Milano Retinex. Land Designator is an alternative calculation described in his 1983 and 86 papers. Later, Jobson used it as the basis of the NASA Retinex. Milano Retinex is a family of slightly different Retinex implementations, here described together with the principal members of this family.
Alessandro Rizzi, "Designator Retinex, Milano Retinex and the locality issue" in Proc. IS&T Int’l. Symp. on Electronic Imaging: Retinex at 50, 2016, https://doi.org/10.2352/ISSN.2470-1173.2016.6.RETINEX-018