I have some geoTIFF topomaps. As far as I know they contain GPS coordnates and the actual topographical map imbedded in the single file. These files are huge - 128MB each and there are a couple of hundred of these.

I want to make a program that allows me to view these files - zoom and move around, all as one map. You can buy such programs but I want to make my own.

I know some C, but have little experience with images and GUIs.

What would the process of displaying these images. Can one simply read each geotiff file - zoom etc using some librays. I am guessing I need to split the files into smaller segments so it can load faster. What about a zoomed out mode? How does google earth do it?

You don't have to buy one.
There are tons of it for free.

If you want to do it anyway,
make yourself familiar with some GUI tool-kits/frameworks in the first place.

If you have chosen one, read the examples.
They usually come with lots of examples for dealing with pictures.

128 meg is not big
at 128 it sounds like a ASTER or GTOPO 30 tile


i am currently working with a map that is 12+ Gig ( c1 Magellan Venus map )
srtm_ramp2.world.86400x43200.bin for the Earth is 3 gig
the Mars MOLA data at 65535x32768 PX is 4 gig

gmic is a good program , it dose have a 4 gig max ( even on a 64 bit system with 12 gig ram)
http://gmic.sourceforge.net/index.shtml
for gmic
will display a 16 bit unsinged ( use "short" for a singed -32767 to 32768 )
most scientific DEM's are in singed LSB format
or for a small 128 meg image
nip2/vip displays 16 bit unsinged and 32 bit float tiff images just fine
http://www.vips.ecs.soton.ac.uk/index.php?title=VIPS

however for a geo referenced DEM if you want to keep the info
use GRASS
http://grass.fbk.eu/

i use ISIS3 from nasa/usgs
http://isis.astrogeology.usgs.gov/index.html



also Cinepaint ( an old GTK1 program) will display a 16 bit tiff