The smallest area represented in a digital image is the:

• A. Image Matrix
• B. Pixel
• C. Voxel
• D. Bit

Answer: (B)

In a digital image, the smallest spatial element is the pixel—the single dot that makes up the picture. Each pixel is a sample that holds brightness or color information for one point in the image, and together all the pixels form the image matrix, the full grid of values. A voxel is the 3D counterpart used in volume imaging, representing a tiny cube of space, so it’s the 3D analogue rather than the 2D case here. A bit is the basic unit of digital data storage, not a spatial sample, though multiple bits may describe a pixel’s color. So the smallest area represented in a 2D digital image is the pixel.