Comments and answers for "Exposing a raster band value and creating an attribute from it"

Comment by garethgis on garethgis's answer

garethgis — Tue, 30 Jan 2018 00:32:58 GMT

Some of the FME tools that look logical just seem a bit of a deadend.I'd have thought that the attribute creator would logically be a reasonable way forward and working on the raster logically faster than converting every pixel to a polygon or point first.The RasterCellCoercer looks like it has the band exposer option while the raster2polygon tool has zero options and didn't automatically bring the band info through to the polygons so I guess its Coercer then merge polygons?

Answer by takashi

takashi — Tue, 30 Jan 2018 00:15:34 GMT

Hi@garethgis, "_band{0}.value" seems to be an element of a list attribute which will be created with a RasterCellCoercer, but I don't think the transformer is used in your workspace, as far as I see your screenshots.

If you need to extract individual cell values as feature attributes, consider using the RasterCellCoercer.

Alternatively, if your final goal is to create polygons each of which merged consecutive cells having the same value, the RasterToPolygonCoercer could be more efficient to accomplish the goal.