Algorithm 2 ML-DWT Compression

Input: ${\mathit{W}}_{\mathbf{4}}$, K Output: $\widehat{{\mathit{W}}_{\mathbf{4}}}$ 1: procedureCompression(${\mathit{W}}_{\mathbf{4}}$, K) 2:     $\mathit{LSI}$ =argsort(${\mathit{W}}_{\mathbf{4}}$, K) 3:     $\widehat{{\mathit{W}}_{\mathbf{4}}}$ =encode(${\mathit{W}}_{\mathbf{4}}$, $\mathit{LSI}$) 4:     return $\widehat{{\mathit{W}}_{\mathbf{4}}}$ 5: end procedure   6: functionargsort(${\mathit{W}}_{\mathbf{4}}$, K) 7:     $\mathit{LSI}=\left\{\right\}$ 8:     $max=0$ 9:     for $j=0$ to $K-1$ do 10:         for $i=0$ to 144 do 11:            if i exists in $\mathit{LSI}$ then 12:                continue 13:            end if 14:            if $abs\left(W\right[i\left]\right)>abs\left(max\right)$ then 15:                $max=W\left[i\right]$ 16:                $index=i$ 17:            end if 18:         end for 19:         $LSI\left[j\right]=index$ 20:         $index,max=0$ 21:     end for 22:     return $\mathit{LSI}$ 23: end function   24: functionencode(${\mathit{W}}_{\mathbf{4}}$, $\mathit{LSI}$) 25:     for $i=0$ to 11 do            ▹${\mathit{A}}_{\mathbf{4}}=W_4[0:11]$ 26:         $A\left[i\right]=W_4\left[i\right]<<4$           ▹ left bit-shift 27:     end for 28:     for $j=12$ to $K-1$ do          ▹$\mathit{D}$$\in W_4[12:144]$ 29:         $D[j-12]=W_4\left[LSI\left[j\right]\right]$ 30:     end for 31:     for $k\in \{0,2,4,6\}$ do 32:         $A\left[j\right]$ = $A\left[j\right]$|( $LSI\left[j\right]$ & 0x000F) 33:         $A[j+1]$ = $A[j+1]$|($\left(LSI\right[j]>>4)$ & 0x000F) 34:     end for 35:     return $\widehat{{\mathit{W}}_{\mathbf{4}}}$ 36: end function