Monday, March 02, 2009

Watermarking Vector GIS Data

A recent posting on the gislist about watermarking vector GIS data led to the link for this interseting article on the topic:

http://www.directionsmag.com/article.php?article_id=195&trv=1

I just skimmed the article, but I plan on reading it in more detail. This is an interesting topic. A common method of watermarking vector GIS data is adding "fake" features, like road segments that don't really exist. But I have often thought that there has got to be better ways of placing a watermark. The tricky part is embedding a watermark that can resist translation, rotation, and scaling. (Or even reprojection to a new coordinate system.) This rules out using any coordinate geometry to record the watermark.

Perhaps using the topology of features that remain intact despite translation, rotation, and scaling would be a valid way to watermark vector GIS data without "polluting" the dataset with fake features.

I'll have to chew on this some more. Might be cool to add a vector GIS data watermarking plug-in to OpenJUMP.

The Sunburned Surveyor

1 comments:

mentaer said...

there is already a watermarking plugin for OpenJUMP:

http://cedric.cnam.fr/~lafaye_j/index.php?n=Main.WaterGoatOpenJumpPlugin

but It doesn't work by adding new objects.