Question

If we use a Laplacian to obtain sharp image for unsharp mask filtered image fs(x, y) of f(x, y) as 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

I have been asked this question during an online exam.

This key question is from Use of Second Order Derivative for Enhancement in portion Image Enhancement of Digital Image Processing

Answer 1

The correct answer is (a) fhb = A f(x, y) – ∇^2  f(x,y)

The explanation: If Laplacian is used to obtain sharp image for unsharp mask filtered image, then

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