doesn't work on extremely large images

[iangilman]

Presumably anything that's too large to fit in RAM.

One possibility (though I haven't played with it): http://www.vips.ecs.soton.ac.uk/ by @jcupitt

[darwinjob]

It’s all about the reader - if the reader is capable of reading a rectangle without decompressing entire image or not. Tiled image formats (like TIFF) suit best for it.

[jcupitt]

Updated libvips link: https://github.com/libvips/libvips