The smallest element of an image is called a _____ and is usually composed of _____ colors.

• A. Voxel, 4
• B. Bit, 1
• C. Pixel, 2
• D. Pixel, 3

Answer: (D)

The smallest element of an image is a pixel, a picture element that holds the color information for a single point. In a typical color image, each pixel gets its color from three color channels—red, green, and blue. Each channel carries a value (often 8 bits), and together they determine the pixel’s final color. That’s why a pixel is usually described as being composed of three colors. A voxel would be the analogous element in a 3D image or volume, not a 2D image. A bit is just a single binary value (0 or 1), which isn’t enough to represent color. Grayscale images use a single intensity value per pixel, but standard color images rely on three color channels.