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Removing a color map from an ST_Raster value

Use the deleteColormap ST_Raster function to remove a color map from an ST_Raster value. Doing so renders the ST_Raster value in grayscale.

  1. Use an UPDATE SQL statement with the deleteColormap function to remove the color map from raster values in those rows in the vegetation table that have a type value equal to deciduous.

    Oracle

    UPDATE VEGETATION t
SET RASTER = t.raster.deleteColormap()
WHERE TYPE = 'DECIDUOUS';

    PostgreSQL

    UPDATE vegetation
SET raster = deleteColormap(raster)
WHERE type = 'deciduous';

    SQL Server

    UPDATE vegetation
SET raster = deleteColormap()
WHERE type = 'deciduous';

    After the deleteColormap successfully completes, the raster value renders as grayscale rather than a color-mapped value.

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