How many gray values does 8-bit depth capture?

• A. 256
• B. 128
• C. 512
• D. 1024

Answer: (A)

With 8-bit depth, each pixel’s gray value is stored in 8 bits, which allows 2^8 = 256 distinct values. Those levels typically range from 0 (black) to 255 (white). So an 8-bit grayscale image has 256 gray levels. Fewer bits give fewer levels (7-bit would be 128), while more bits give more levels (9-bit would be 512, 10-bit would be 1024).