topic Re: Inverted terrain features in Data Management Questions

Inverted terrain features

Anonymous User — Wed, 12 Jun 2013 12:00:52 GMT

Original User: jimcousins

Greetings,
I have some aerial imagery with the shadowing causing terrain features to be inverted - hills look like depressions and gullies look like ridges (see attachment Aerial unchanged.jpg). Is there any way to alter this so it looks correct without rotating the data frame (what is should look like is attachment Aerial rotated.jpg).

Re: Inverted terrain features

Anonymous User — Wed, 12 Jun 2013 19:43:42 GMT

Original User: sarajase

Appears to be scanning error/artifact.

Perhaps nothing much could be done about it other than to rescan

By some chance it is not a product of some digital mapping camera (such as MS Vexcel or Leica ADS80), isn't it?

Thanks

Re: Inverted terrain features

JimCousins — Wed, 12 Jun 2013 20:26:37 GMT

You misunderstand. This is not an artifact from scanning, it is an optical illusion created by the direction of the shadows on the ground during the image capture from the airplane. the two photos show the same extents and the same groundsurface, but the features that are raised appear sunken and the features that are sunken appear raised. When you rotate the photo 180 degrees, the features invert and what was sunken appears raised and what was raised appears sunken.
My question is what method exists (if any) that will produce the inversion of features without rotating the image.
Regards,
Jim