Given $4 \times 4$ 4-bit reference and input images, use histogram matching to restore the input image.
*(i) The reference and input images, respectively, are
$$
\left[\begin{array}{llll}
4 & 4 & 3 & 3 \\
4 & 4 & 4 & 3 \\
5 & 4 & 4 & 4 \\
4 & 4 & 4 & 4
\end{array}\right]\left[\begin{array}{rrrr}
15 & 15 & 0 & 0 \\
15 & 15 & 15 & 0 \\
15 & 15 & 15 & 15 \\
15 & 15 & 15 & 15
\end{array}\right]
$$
(ii) The reference and input images, respectively, are
$$
\left[\begin{array}{llll}
3 & 3 & 3 & 3 \\
3 & 3 & 3 & 3 \\
3 & 2 & 2 & 3 \\
2 & 2 & 2 & 2
\end{array}\right]\left[\begin{array}{rrrr}
15 & 15 & 15 & 15 \\
15 & 15 & 15 & 15 \\
15 & 0 & 0 & 15 \\
0 & 0 & 0 & 0
\end{array}\right]
$$
(iii) The reference and input images, respectively, are
$$
\left[\begin{array}{llll}
3 & 5 & 5 & 3 \\
4 & 4 & 4 & 3 \\
4 & 2 & 3 & 4 \\
4 & 2 & 2 & 3
\end{array}\right]\left[\begin{array}{rrrr}
0 & 15 & 15 & 0 \\
15 & 15 & 15 & 0 \\
15 & 0 & 0 & 15 \\
15 & 0 & 0 & 0
\end{array}\right]
$$