The correct option is (c) Assign gray level to the new pixel using its four nearest neighbors
Best explanation: Bilinear interpolation uses the four nearest neighbors of the new pixel. Let (x’, y’) is the coordinates of a point in the zoomed image and the gray level assigned to the point is v(x, y’).
For bilinear interpolation, the assigned gray level is given by
v(x’, y’) = ax’ + by’ + cx’y’ + d
Here, a, b, c and d are determined from the four equations in four unknowns that can be written using the four nearest neighbors of point (x’, y’).