Hi Dario,

I'm not sure I follow you here... I would indeed be interested to
see the .TXT database you've built, but am not clear on what it
contains? RA/dec values for individual pixels? Or... ?

Some time ago, I found a site with some images from historical atlases:

http://www.lhl.lib.mo.us/events_exhib/exhibit/ex_atlas.shtml

and attempted to add these images to Guide charts. I encountered
two problems: aligning the images was more difficult than I expected,
and there is some significant distortion when adding images with so
large a field of view. (The system Guide uses for displaying DSS and
RealSky images is a simple one: for each image, the RA/dec coordinates
of the four corners is given. Guide finds out the on-screen pixel
coordinates corresponding to each of those four corners, and stretches
the image to fit that quadrilateral. This works wonderfully for images
up to, say, ten degrees or so. Beyond that point, the image isn't
really "flat" enough for this simple method to work.)

-- Bill