$ go install github.com/posener/tiler/cmd/tiler
$ tiler -h
Usage of tiler:
  -colors string
    	Scale tiles colors.
    	Use a number 'n' to define number of scales of each color component.
    	Use comma separated numbers 'r,g,b' to have different number of scales to each color component.
  -img string
    	Image to tile. Required.
  -out string
    	Destination path.
  -overlap
    	Can tiles overlap each other.
  -rotate string
    	Rotate tiles. Comma separated list of rotations in range [0..1].
  -scale string
    	Scale tiles. Comma separated list of scale factors.
  -shift string
    	Grid shifts in the format: 'x,y'. If omitted, tile size will be used.
  -tiles string
    	Path to tiles directory or a tile file. Required.