I am working on creating data for a regional (as opposed to just our county) bicycle path map.

A lot of surrounding municipalities do not have GIS or CAD systems. They send us their bicycle maps on paper. I scan them on a large format scanner and then load the image into my GIS application. I also load a GIS layer that occupies the same space as the scanned image.

Right now I am digitizing map a city sent me that just used a marker to draw their bike paths on a cadastral plat!

I find a feature on the scanned image and click on it, and then I find the same feature on our GIS layer and click on it. I do this a minimum of three times. If it looks like all of the features on the scanned image match up with our existing GIS layers I create what is called a georeferenced image from the scanned image. All that means is that every point on the scanned image now has an associated latitude and longitude. It has become a true GIS layer.

A slang term for georeferencing is rubber sheeting because the program will stretch and distort the scanned image a little bit in order to make it fit where it needs to in space, sort of like a rubber sheet.

Then I load the georeferenced image into my GIS application and click along the bicycle paths to create the new bicycle path features for us to use in our regional map.

We are having the cartography lab of a local university create the map for us, but we have to send them the feature data.