We were recently contacted by Zachary Bortolot an Associate Professor in the Geographic Science Program at James Madison University. He has been developing a method of realistically colorising black and white historical aerial images. His method is automated and intelligently transfers colour from recent colour imagery of a location to historical black and white imagery of the same location. His algorithm appears to be able to handle changing landscapes although exact details as to how it does it are not given. Read more about it on his website.

You can also download some sample image overlays to view in Google Earth. Below are just small samples of the images, comparing them with Google Earth imagery. Be sure to download the overlays to explore all the imagery.

Colorized aerial image, Palm Springs, California, 1972 vs Google Earth image.

Colorized aerial image, Harrisonburg, Virginia, 1974 vs Google Earth image.

Colorized aerial image, Washington, D.C., 1951 vs Google Earth image.

In the case of Washington D.C. Google Earth has an aerial image from 1949 but the colorized image is better quality.

Colorized aerial image, Washington, D.C., 1951 vs Google Earth historical imagery 1949.

Most countries around the world have large collections of aerial imagery gathered over the years, much of which have never been digitised. It would be great to see more of this imagery in Google Earth and even better if it is colourised.