a. [4 marks] Find an expression for i' and j' (the transformed coordinates) in terms of i and j (the original coordinates). b. [3 marks] Using the backward-mapping approach and nearest neighbour interpolation, find the coordinates of the input pixel (i, j), the gray level of which should be assigned to the output pixel (i', j') = (100, 150). c. [3 marks] Using bilinear interpolation, find the gray level at (i, j) = (221.3, 396.7). A table of gray-level values in the input image is given below. I(i, j) I(221, 396) = 18 I(221, 397) = 45 I(222, 396) = 52 I(222, 397) = 36 d. [2 marks] What is the main benefit of bilinear interpolation over the nearest neighbour method? What is a disadvantage of bilinear interpolation over the nearest neighbour method? 5. An image (Figure 2) is generated and stored in the variable im using the following sequence of MATLAB commands: >> im = uint8 ( zeros (512) ) ; > > im (32: 63, 128:255) =255