(a) In block based video motion estimation, the three-step search with a search area of +7 pixels is considered to form the prediction of the current frame from the reference frame. With the help of simple diagrams, describe the steps of the three-step search. (5 Marks) (b) If a search area of +7 pixels is considered to form the prediction of the current frame from the reference frame and the block size of the frame is 8x8 pixels, (i) (ii) calculate the number of search points for each block for the three-step search, and calculate the number of multiplications if the matching criteria are the mean square error (MSE) and the mean absolute error (MAE), respectively (8 Marks) (c) A block of 2x2 pixels in the current frame is shown in Figure 4 and its corresponding block in the reference frame is shown in the shaded area in Figure 5. Within a search window of 1 pixels, find the best-matched motion vector and the corresponding best-matched block in Figure 5 if the matching criterion is based on: (i) the (ii) the mean absolute error (MAE). mean square error (MSE); 25 25 20 20 20 20 1015 20 15 1010 15 10 105 20 20 10 0 Figure 4 Figure 5 (a) In block based video motion estimation, the three-step search with a search area of +7 pixels is considered to form the prediction of the current frame from the reference frame. With the help of simple diagrams, describe the steps of the three-step search. (5 Marks) (b) If a search area of +7 pixels is considered to form the prediction of the current frame from the reference frame and the block size of the frame is 8x8 pixels, (i) (ii) calculate the number of search points for each block for the three-step search, and calculate the number of multiplications if the matching criteria are the mean square error (MSE) and the mean absolute error (MAE), respectively (8 Marks) (c) A block of 2x2 pixels in the current frame is shown in Figure 4 and its corresponding block in the reference frame is shown in the shaded area in Figure 5. Within a search window of 1 pixels, find the best-matched motion vector and the corresponding best-matched block in Figure 5 if the matching criterion is based on: (i) the (ii) the mean absolute error (MAE). mean square error (MSE); 25 25 20 20 20 20 1015 20 15 1010 15 10 105 20 20 10 0 Figure 4 Figure 5