Algorithm 3.

Post refinement to improve robustness.

1:  function POST REFINEMENT(pext)

2:   ppast ← pext(1)

3:   pcurrent ← −1

4:   count ← 0

5:   idxbgn ← 1

6:   idxfin ← 0

7:   pre(1:T) ← −1

8:   for t = 1 to T do

9:   pcurrent = pext(t)

10:   if pcurrent ≠ ppast then

11:   idxfin = t−1

12:   if count>phist then

13:   pre(idxbgn:idxfin) = ppast

14:   idxbgn = t

15:   count = 1

16:   else

17:   pre(idxbgn:idxfin) = pcurrent

18:   count = count+1

19:   end if

20:   else

21:   count = count+1

22:   end if

23:   ppast = pcurrent

24:   end for

25:   return pre

26:  end function