Map Algebra
Combining raster or feature layers often involves Boolean combinations of raster or vector layers. These Boolean operators are shown here as Venn diagrams or vector overlays, where red is the “result” of combining A and B with different operators or tools.
and satisfies both conditions simultaneously
or satisfies one or the other and both
not (difference) excludes the 2nd condition
xor (symmetrical difference) satisfies one or the other but not both
In QGIS, “xor” does not exist as an operator in the Raster Calculator, but implemented as “symmetrical difference” in vector overlays.
Raster Boolean Overlay (Vector on the next page)
In QGIS, Raster Calculator, some logical tools are available in as raster calculator operators (left) and some as individual processing tools (right).
In ArcGIS Pro, Raster Calculator expressions (left) are also available individually as tools (right).
edited by DJH Jan 15, 2026