[GRASSLIST:5308] comparing two different maps

[Abhay Kulkarni]

Hi all.

My first map was a tiff image of 2540 x 3500 pixels of 300 dpi resolution 
with a scale of 1:63000. I created a xy location, imported that raster map 
and digitized.

My second map covers the same geographic area, but image size is 512 x 512 
pixels with 90 dpi resolution, scale unknown (it is a tif image converted 
from a satellite image).

I want to digitise this map and compare the two layers. I don't know whether 
it will be possible and am confused. Should lat-lang coords are must ? or 
image transformation ? ...

Please help.

Thank you.
Regards,
Abhay.