11. The Laplacian is which of the following operator?
A. Nonlinear operator
B. Order-Statistic operator
C. Linear operator
D. None of the mentioned
12. A Laplacian for an image f(x, y) is defined as: is given by ________
A. [f(x + 1, y) + f(x – 1, y) – 2f(x, y)] and [f(x, y + 1) + f(x, y – 1) – 2f(x, y)] respectively
B. [f(x + 1, y + 1) + f(x, y – 1) – 2f(x, y)] and [f(x , y + 1) + f(x – 1, y) – 2f(x, y)] respectively
C. [f(x, y + 1) + f(x, y – 1) – 2f(x, y)] and [f(x + 1, y) + f(x – 1, y) – 2f(x, y)] respectively
D. None of the mentioned
13. The Laplacian ∇2 f=[f(x + 1, y) + f(x – 1, y) + f(x, y + 1) + f(x, y – 1) – 4f(x, y)], gives an isotropic result for rotations in increment by what degree?
A. 90o
B. 0o
C. 45o
D. None of the mentioned
14. The Laplacian incorporated with diagonal directions, i.e. ∇2 f=[f(x + 1, y) + f(x – 1, y) + f(x, y + 1) + f(x, y – 1) – 8f(x, y)], gives an isotropic result for rotations in increment by what degree?
A. 90o
B. 0o
C. 45o
D. None of the mentioned
15. Applying Laplacian has which of the following result(s)?
A. Produces images having greyish edge lines
B. Produces image having a featureless background
C. All of the mentioned
D. None of the mentioned
16. Applying Laplacian produces an image having featureless background which is recovered maintaining the sharpness of the Laplacian operation by either adding or subtracting it from the original image depending upon the Laplacian definition used. Which of the following is true based on the above statement?
A. If the definition used has a negative center coefficient, then subtraction is done
B. If the definition used has a positive center coefficient, then subtraction is done
C. If the definition used has a negative center coefficient, then the addition is done
D. None of the mentioned
17. A mask of size 3*3 is formed using Laplacian including diagonal neighbors that have a central coefficient of 9. Then, what would be the central coefficient of the same mask if it is made without diagonal neighbors?
A. 5
B. -5
C. 8
D. -8
18. Which of the following mask(s) is/are used to sharpen images by subtracting a blurred version of the original image from the original image itself?
A. Unsharp mask
B. High-boost filter
C. All of the mentioned
D. None of the mentioned
19. Which of the following gives an expression for a high boost filtered image file, if f represents an image, f blurred version off, fs unsharp mask filtered image, and A ≥ 1?
A. fhb = (A – 1) f(x, y) + f(x, y) – f x, y)
B. fhb = A f(x, y) – f(x,y)
C. fhb = (A – 1) f(x, y) + fs(x, y)
D. All of the mentioned
20. If we use a Laplacian to obtain a sharp image for unsharp mask filtered image fs(x, y) of f(x, y) as the input image, and if the center coefficient of the Laplacian mask is negative then, which of the following expression gives the high boost filtered image fhb, if ∇2 f represent Laplacian?
A. fhb = A f(x, y) – ∇2 f(x,y)
B. fhb = A f(x, y) + ∇2 f(x,y)
C. fhb = ∇2 f(x,y)
D. None of the mentioned