Hi Guys,
Although I write in C, this is more of an English question.

I wrote a vector based GPS mapping program that works nicely
It would be nice to use satellitte imagery underneath the topographic
vector data.
I've done a vector GPS on two platforms now, but never thought about
an image based GPS before.

Basically, I'd like an English description of how this works.
How the image tiles are referenced for example, are hi-res images
resized when zooming out? (this one will have map tile images stored offline).
Are the image tiles referenced with coordinates?

I do already have a lot of information, like the geographic coordinates
of each corner, and centre of the screen for whatever zoom level
or map position you are viewing, and what the value of a single
pixel is relating to incrementing a decimal lat/long value, rotation
angle, and basically any variables that you'd know by having a GPS
mapper already working.

Any ideas appreciated!
Art.