ESRI World Files (.wld) for files from http://visibleearth.nasa.gov/view.php?id=73751
Download the high-resolution images:
wget http://eoimages.gsfc.nasa.gov/images/imagerecords/73000/73751/world.topo.bathy.200407.3x21600x21600.A1.jpg
wget http://eoimages.gsfc.nasa.gov/images/imagerecords/73000/73751/world.topo.bathy.200407.3x21600x21600.A2.jpg
wget http://eoimages.gsfc.nasa.gov/images/imagerecords/73000/73751/world.topo.bathy.200407.3x21600x21600.B1.jpg
wget http://eoimages.gsfc.nasa.gov/images/imagerecords/73000/73751/world.topo.bathy.200407.3x21600x21600.B2.jpg
wget http://eoimages.gsfc.nasa.gov/images/imagerecords/73000/73751/world.topo.bathy.200407.3x21600x21600.C1.jpg
wget http://eoimages.gsfc.nasa.gov/images/imagerecords/73000/73751/world.topo.bathy.200407.3x21600x21600.C2.jpg
wget http://eoimages.gsfc.nasa.gov/images/imagerecords/73000/73751/world.topo.bathy.200407.3x21600x21600.D1.jpg
wget http://eoimages.gsfc.nasa.gov/images/imagerecords/73000/73751/world.topo.bathy.200407.3x21600x21600.D2.jpg
Place them in the same directory as the .wld files bellow.
Drag&drop the files into MapTiler Pro - or use the command line: maptiler -o output *.jpg
Prepared for MapTiler: http://www.maptiler.com/ or other GDAL tools