Algorithm 1 Optimal warping path algorithm

Input Accumulated cost matrix D Output optimal warping path $p^{*}$ 1:$i\leftarrow N,j\leftarrow M,p_1\leftarrow (i,j),l\leftarrow 1$ 2:while$i\ne 1$ OR $j\ne 1$ do 3:    $l\leftarrow l+1$ 4:    if $i=1$ then 5:        $p_l\leftarrow (i,j-1)$ 6:        $j\leftarrow j-1$ 7:    else 8:        if $j=1$ then 9:           $p_l\leftarrow (i-1,j)$ 10:           $i\leftarrow i-1$ 11:        else 12:           $d^{*}\leftarrow min\{D_{i-1,j-1},D_{i-1,j},D_{i,j-1}\}$ 13:           if $d^{*}=D_{i-1,j}$ OR $d^{*}=D_{i-1,j-1}$ then 14:               $i\leftarrow i-1$ 15:           end if 16:           if $d^{*}=D_{i,j-1}$ OR $d^{*}=D_{i-1,j-1}$ then 17:               $j\leftarrow j-1$ 18:           end if 19:           $p_l\leftarrow (i,j)$ 20:        end if 21:    end if 22:end while 23:$p^{*}=reverse\left(p\right)$