Got this when removing np.array() call
```python
Error compiling Cython file:
------------------------------------------------------------
...
    width = segments.shape[2]

    #neighborhood arrays
    cdef Py_ssize_t[::1] ddx = [1, -1, 0, 0, 0, 0]
    cdef Py_ssize_t[::1] ddy = [0, 0, 1, -1, 0, 0]
    cdef Py_ssize_t[::1] ddz = [0, 0, 0, 0, 1, -1]
                              ^
------------------------------------------------------------

skimage/segmentation/_slic.pyx:184:31: Cannot coerce list to type 'Py_ssize_t[::1]'
```