I am working with some very large images of the earth for a mapping class I am working on for a few projects I have in mind. Since the images are as large as they are it is impractical to load the whole thing into memory. For my medium sized image (21600X10800px) I chopped it up into smaller tiles and loaded those. This took all the computing power I possess to chop it up with imagemagick. So the image I have now at 4x the size is too big to handle.

The solution I am thinking of is to somehow grab a portion of the larger image if I know the coordinates. Only problem is I think I would need to load the image into memory to do this which is something I dont want to do. I am working with Qt 4.4 currently. I am also open to any and all ideas for large image handling

The images I am working with are from here: http://earthobservatory.nasa.gov/Fea..._monthlies.php and I have handled the smaller 2 sizes it is the big 2GB image I am working on now