  One-shot imitation is the vision of robot programming from a single
demonstration, rather than by tedious construction of computer code. We present
a practical method for realizing one-shot imitation for manipulation tasks,
exploiting modern learning-based optical flow to perform real-time visual
servoing. Our approach, which we call FlowControl, continuously tracks a
demonstration video, using a specified foreground mask to attend to an object
of interest. Using RGB-D observations, FlowControl requires no 3D object
models, and is easy to set up. FlowControl inherits great robustness to visual
appearance from decades of work in optical flow. We exhibit FlowControl on a
range of problems, including ones requiring very precise motions, and ones
requiring the ability to generalize.
