Table 2 Calculation of \(\psi _{\eta,\theta }^{\widetilde {f},f,p}\)

Step 1

Calculate the location of the starting point of the η _th MB of \(\widetilde {f}_{\times {th}}\) frame, \(\left (m_{x}^{\widetilde {f}} (\eta),m_{y}^{\widetilde {f}} (\eta)\right)\).

Step 2

Obtain the position of the SB θ of MB η, \(\left (s_{x}^{\widetilde {f}}(\eta,\theta),s_{y}^{\widetilde {f}}((\eta,\theta))\right)\) based on the extracted MB partition modes.

Step 3

With knowing the motion vector the SB θ of MB η between f and \(\widetilde {f},(MVx^{\widetilde {f},f}(\eta,\theta),MVy^{\widetilde {f},f}(\eta,\theta))\), the location of the starting point of the SB used as the reference of frame f can be derived by

\( \left \{ \begin {array}{l} l_{x}^{\widetilde {f},f} (\eta,\theta) = s_{x}^{\widetilde {f}} (\eta,\theta) + MVx^{\widetilde {f},f}(\eta,\theta) \\ l_{y}^{\widetilde {f},f} (\eta,\theta) = s_{y}^{\widetilde {f}} (\eta,\theta) + MVy^{\widetilde {f},f}(\eta,\theta) \\ \end {array} \right. \)

Step 4

The region of the pixels of the f frame referenced by the SB θ of the MB η of the frame \(\widetilde {f}\) can be expressed by

\(\phi _{\eta,\theta }^{\widetilde {f},f} = \left \{(x,y)\mid l_{x}^{\widetilde {f},f}(\eta,\theta) \leq x\leq l_{x}^{\widetilde {f},f}(\eta,\theta)+w^{\widetilde {f}}(\eta,\theta)-1, l_{y}^{\widetilde {f},f} \leq y\leq l_{y}^{\widetilde {f},f}+h^{\widetilde {f}}(\eta,\theta)-1\right \}\),

where \(w^{\widetilde {f}}(\eta,\theta)\) and \(h^{\widetilde {f}}(\eta,\theta)\) are the width and the height of the SB θ of MB η, respectively.

Step 5

Let φ _f,p specify the region of the pixels of packet p of frame f. Eliminate the elements in \(\phi _{\eta,\theta }^{\widetilde {f},f}\) that do not belong to the set φ _f,p and obtain the set of the pixels referenced by the SB θ of the MB η of the frame \(\widetilde {f}\), \(\psi _{\eta,\theta }^{\widetilde {f},f,p}\), \(\psi _{\eta,\theta }^{\widetilde {f},f,p} =\phi _{\eta,\theta }^{\widetilde {f},f} \cap \varphi _{f,p}\).

Step 6

Repeat step 1–step 5 if there are unprocessed SBs of frame \(\widetilde {f}\).