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RS_Polygonize

Converts a raster band into polygons grouped by connected pixel value regions.

Usage

list RS_Polygonize(rast: raster, band: integer)

Arguments

  • rast (raster): Input raster
  • band (integer)

Description

Converts the specified raster band into vector polygons, returning one item per connected region of pixels that shares the same value.

Each returned list item contains:

  • geom: the polygon geometry encoded as WKB
  • value: the pixel value represented by that polygon

Examples

SELECT RS_Polygonize(RS_Example(), 1);

┌──────────────────────────────────────────────────────────────────────────────┐
│                     rs_polygonize(rs_example(),Int64(1))                     │
│                                     list                                     │
╞══════════════════════════════════════════════════════════════════════════════╡
│ [{geom: {item: POLYGON((43.08 79.07,44.08 81.07,46.08 82.07,45.08 80.07,43.… │
└──────────────────────────────────────────────────────────────────────────────┘