Digital map to .png or .jpg or .gif
I've been trying software and waiting for maps to download and i can't come to the end result i want so that's why i'm making this topic.
I want to use the ETOPO1 format ice-surface map from http://www.ngdc.noaa.gov/mgg/global/global.html as a greyscale heightmap. I have downloaded and tried GEODAS and was able to get a blue shade map of the world but i can't export it as an image in it :( screencapture won't work because the map is a way bigger resolution as my screen supports. And scaling it up afterwards would get quircky.
An other solution would be to somehow merge the heightmap and bathymetric map from http://earthobservatory.nasa.gov/Fea..._monthlies.php but the color shades would mix up i guess but if it's possible i'm open to it. I don't expect it is but just to be sure.
So yeah, i basiclly am looking for a heightmap (as an image file, TIF?) of both under and above water terrain, with the ice cap on top of it for the poles in a size of atleast 21600*10800. I'm OK with downscaling. I'm willing to install freeware or trial software whatever. I'm just seriously annoyed at this point i couldn't figure it out after 5 hours of googling and trying stuff out that i have to bother you with the question :(