I have written a function called geoimread which lets you read sections of a large geotiff or GeoJP2. I recently managed to workaround a mapping toolbox dependency in geoimread, and for that reason I have now included it in ImGRAFT.
Additionally we have included two other functions called animatepair and alphawarp. animatepair is useful for inspecting image pairs and troubleshooting. alphawarp is a helper function can help you drape your results semi-transparently over a background image.