When the matrix size of a digital image decreases, what happens to the number of pixels?

When the matrix size of a digital image decreases, what happens to the number of pixels?

• A. Decreases
• B. Increases
• C. Cannot be determined
• D. Remains the same

Answer: (B)

Pixel count is determined by width times height of the image matrix. When the matrix size decreases, the number of samples across the image drops in one or both directions, so the total number of pixels becomes smaller. For example, going from 512×512 to 256×256 reduces the pixel count from 262,144 to 65,536. In imaging terms, reducing the matrix size lowers resolution and typically reduces file size as well. Conversely, increasing the matrix size increases the number of pixels.

Pixel count is determined by width times height of the image matrix. When the matrix size decreases, the number of samples across the image drops in one or both directions, so the total number of pixels becomes smaller. For example, going from 512×512 to 256×256 reduces the pixel count from 262,144 to 65,536. In imaging terms, reducing the matrix size lowers resolution and typically reduces file size as well. Conversely, increasing the matrix size increases the number of pixels.