The files in the Images directory and its subdirectories  comprise  sets
of images intended to be used as textures, in the normal English meaning
of the word, as distinct to images intended to be used as pictures.

Currently the following sets of subdirectories are provided

   Noise - 64x64
   Noise - 256x256
   Surfaces - 512x512
   Tileable - 512x512

The two Noise subdirectories contain images of random noise. Their main
purpose is for use as a noise source in shaders that require it.

The "Surfaces - 512x512" subdirectory contains a number images intended
to be used as surface textures. Each image is 512 pixels wide and high.

The "Tileable - 512x512" directory contains a subset of the images that
are in the "Surfaces - 512x512" subdirectory,  this  subset being those
can be seamlessly tiled in both the X and the Y directions.