| Author | Technique used/work done |
| | used the Spanish cadastre plug-in for Google EarthTM to segregate building roof areas |
| | created a 3-D city model using digital orthophoto and digital elevation data of Bardejov city in eastern Slovakia with a spatial resolution of 1m |
| | applied a ArcGIS extension named “Feature Analyst” on high resolution orthophotos of Ontario, Canada |
| | used buildings’ polygon obtained through digitization of orthophotoes of Israel |
| Ramachnadra et al., 2014 | estimated rooftop solar photovoltaic potential of Uttara Kannada, India, by digitizing rooftop area of a household in selected villages |