What does pixel bit depth primarily determine in a digital image?

• A. Number of grayscale shades
• B. Spatial resolution
• C. Frame rate
• D. Color channels

Answer: (A)

Pixel bit depth sets how many different brightness values a single pixel can represent. In grayscale images, each pixel maps to one brightness level, so more bits mean more possible shades of gray. For example, 8-bit depth yields 256 gray levels, while 16-bit depth yields 65,536 levels, allowing much finer tonal variation.

Spatial resolution is about how many pixels are in the image (the width and height), not how many tones each pixel can show. Frame rate relates to how many frames appear per second in video. Color channels refer to how many color components you have (like red, green, blue); bit depth per channel increases tonal detail within those channels, but doesn’t by itself change the number of grayscale shades when thinking about a grayscale image.

So the primary determinant of how many grayscale shades you can display is the pixel bit depth.