Orthophotography is a process by which vertical aerial photographs are projected to eliminate geometric distortions due to image perspective and produce images that are equivalent to conventional Planimetric maps. Orthophotography preserves information from aerial photographs by displaying geographically accurate image features instead of vector drawings. 

Producing orthophotography mosaics involves applying horizontal and vertical corrections as well as radiometric balancing. Geometric corrections are applied so that each pixel is horizontally accurate and is also rectified to account for the effects of relief displacement. The final stage in the process involves radiometric and tonal balancing so that all images blend well together, and are visually pleasing. The resultant image is an ortho-rectified image map that can be referenced to any known ground system.