The Locus Filter

Research output: Contribution to conferencePaperpeer-review


We study the design of a particular filter for digital photography, that we call the Locus Filter. It is built in a way that guarantees that the light in the scene after applying the filter stays on the Planckian locus. In this paper we provide a physical basis for designing such a filter based on the Wien approximation of Planck’s law. While locus filtered Planckian lights are on the locus, the amount they shift depends both on the locus filter and the colour temperature of the light. In experiments we show that real lights shift more or less as if they were Planckian in terms of the changes in their correlated colour temperatures.
Original languageEnglish
Publication statusPublished - 2021
EventThe Congress of the International Color Association : AIC 14th Congress Milano 2021 - Milano, Italy
Duration: 30 Aug 2021 → …
Conference number: 14


ConferenceThe Congress of the International Color Association
Abbreviated titleAIC
Period30/08/21 → …


  • Filter design
  • Colour temperature
  • Wien approximation
  • Planckian locus

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