provided by extensions.  The number of compressed texture formats
            supported can be obtained by querying the value of
            <code class="constant">GL_NUM_COMPRESSED_TEXTURE_FORMATS</code>.  The list of specific
            compressed texture formats supported can be obtained by querying the value of
            <code class="constant">GL_COMPRESSED_TEXTURE_FORMATS</code>.
        </p><p>The required compressed formats are paletted textures.
        The layout of the compressed image is a
   