anchor: CompressedImageData:getHeight
  Gets the height of the CompressedImageData.
  height = CompressedImageData:getHeight()
  height number The height of the CompressedImageData.
  height = CompressedImageData:getHeight( level )
  level number A mipmap level. Must be in the range of CompressedImageData:getMipmapCount().
  height number The height of a specific mipmap level of the CompressedImageData.