.. meta:: :description: Overview of the histogram docker. .. metadata-placeholder :authors: - Wolthera van Hövell tot Westerflier - Scott Petrovic :license: GNU free documentation license 1.3 or later. .. index:: ! Histogram .. _histogram_docker: ================ Histogram Docker ================ A Histogram is a chart that shows how much of a specific channel value is used in an image. Its purpose is to give a really technical representation of the colors in an image, which can be helpful in decision making about filters. .. image:: /images/dockers/Histogram_docker.png The histogram docker was already available via :menuselection:`Layers --> Histogram`, but it's now a proper docker. External Links: * `Wikipedia's entry on image histograms `_.