GATE DA 2025 Q3: Count pixels with intensity U ≤ 4 in a 4 × 4 image

A $4 \times 4$ digital image has pixel intensities $(U)$ as shown in the figure. The number of pixels with $U \le 4$ is:

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Answer: C (official GATE 2025 final answer key)

Concept used: Reading data from a grid and counting values against a condition.

First step: Go row by row and count the entries that are at most 4: the first row has 4 such pixels and the second has 3.

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Source: official GATE 2025 DA question paper and final answer key, organised by IIT Roorkee. Question paper · Answer key