Tag: geoai

An orthophoto is one aerial photograph corrected to a map. An orthomosaic is many of them stitched into one image. Which one you have, and where the seams are.

Semantic segmentation labels every pixel with a class: building or not. Instance segmentation draws every building as its own object. On a terraced street the difference is one polygon against forty.

A DSM is the height of the top of everything: roofs, treetops, bare ground. A DTM is bare ground alone. Subtract one from the other to get what stands on it.

Five ways to show a street rebuilt, from hand-drawn vector layers to a generated aerial view. Only one gives back a picture that stays on the map.

From the official hazard map to a generated aerial view of the water. Which method gives a number, which gives a picture, why an elevation model changes both.

For a classified raster, use Raster > Conversion > Polygonize. Here are the five methods, the fix for staircase edges, and what to do with a photograph.

A building footprint is the outline where a building meets the ground. Most downloadable ones follow the roof. The difference, floor area, and the open data.

GeoAI is machine learning run on geographic data. The five things it extracts today, what it costs in hardware and time, and how to run it in QGIS.