In digital imaging, the basic unit of the image is called a

• A. Pixel
• B. Segments
• C. Voxel
• D. Cell

Answer: (A)

In digital imaging, images are built from tiny picture elements called pixels. Each pixel is the smallest element in the image grid and carries the color and brightness information for that point. When you line up all the pixels in a grid, you get the complete image. In 3D or volume imaging, the equivalent smallest unit is a voxel, not a 2D pixel. Segments refer to regions identified by analysis, and “cell” isn’t a standard term for the basic image unit. So the basic unit of the image is the pixel.