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Incubating

Incubating — Raster Styling

Status: open, under discussion (#41).

Portolan's Visualization Styles requirements are currently vector-only: the concrete style format, defined in formats.md, is a MapLibre GL style file for PMTiles. How raster styles are expressed is unspecified.

Open questions:

  • Colormaps — how a continuous raster's color ramp is declared so a client can colorize it at draw time (e.g. via the STAC render extension and the required min/max statistics).
  • Legends — how a categorical raster maps pixel values to labels and colors.
  • Continuous vs. categorical vs. multiband — whether these need distinct style representations, and how a client tells them apart.

Until this is settled, a display-ready COG (embedded color table, or a continuous raster colorized from its embedded min/max statistics) satisfies the "render from source" path in core and needs no separate style file. This document will graduate into core.md / formats.md once the expression is agreed.