Question

The value at the center pixel of the image at (1) obtained after applying the filter given at (2) is .................. 

• A. 70
• B. 68
• C. 69
• D. 71

Hint:

A $3\times3$ mean filter replaces each pixel by the average of its 9 neighbors; it smooths noise but blurs edges.

Answer 1

The Correct Option is A

The filter is a $3\times3$ mean (box) filter with all coefficients $\frac{1}{9}$. The new center value is the average of the $3\times3$ neighborhood:
Image block: \[ \begin{matrix} 67 & 67 & 72 \\ 70 & 68 & 71 \\ 72 & 71 & 72 \end{matrix} \] Sum $=67 + 67 + 72 + 70 + 68 + 71 + 72 + 71 + 72 = 630$.
Mean $= \frac{630}{9} = 70$. Hence, the center becomes \(\boxed{70}\).