Use NumPy's `copyto` to copy `image` to `out`
Use NumPy's `copyto` to copy `image` to `out`

Drop the `id` check and just use NumPy's `copyto`. Internally NumPy
checks to see if this `out` is the same as `image`, so there is no need
for us to do this explicitly as we gain this optimization for free.

jakirkham/rank_filter,nanshe-org/rank_filter,nanshe-org/rank_filter,DudLab/rank_filter,DudLab/rank_filter,nanshe-org/rank_filter,jakirkham/rank_filter,jakirkham/rank_filter,DudLab/rank_filter