[Xastir] georeferencing maps on osx?

[Derrick J Brashear]

On Tue, 28 Dec 2004, Tom Russo wrote:

> Ouch.  Well after the 100th or so you'll be so familiar with the procedure
> it'll be a piece of cake to do the remaining 800.  I can't think of any simple
> way to automate it with rasters that don't start out georeferenced and that
> you scanned yourself.  If you find one, I'd be delighted to hear of it.

If I only did 4 points i could cheat and software-recognize the neatline 
corners. I'd still have to give values but it would be better than 
clicking. And it would be rough, but for maps this old it's only going to 
be an approximation anyway.

> 1)  Scan map with appropriate resolution to give the meters-per-pixel you want.
>   (for a 1:24K map 300dpi leads to about 2m/pixel)

They're all 200dpi, iirc, and there's not a chance i'm rescanning; i only 
scanned about 1/3 of them in the first place.

> It is not actually all that difficult, but with 900 rasters to do I'd probably
> try to end-run the process and look for some source of previously digitized
> and georeferenced files instead.

Who scanned historical USGS maps before?

http://historical.maptech.com/

You can find joined images here, it took a monthlong batch job to just get 
these:
http://usgshist.dementia.org/joined/