Q10,paper 3,j 12In an image compression system 16384 bits are used to represent 256 × 256 image with 256 gray levels. What is the compression ratio for this system ?

Options (A) 1 (B) 2 (C) 4 (D) 8 ,
Answer (B) 2.
Explanation. For photographic images, Compression Ratio is usually below 2 for lossless, but can reach over 10 for lossy compression. 256 gray levels can be represented by 8 bits. So a pixel can be represented by 8 bits.so total storage required is 256*256*8 bits. It is represented by 16384 bits. So compression ratio is 256*256*8/16384 . it turns out to be 32.