Table 3: Known acceptable value in image quality measurement.

NumberImage quality measurementKnown acceptable value

1Peak signal-to-noise ratio (PSNR)≥42 dB, greater than or equal to 42 db is better
2Universal image quality index~1.0, near to 1.0 is perfect
3Signal-to-signal noise ratio (SNR)≥20 dB, greater than or equal to 20 db is better
4Structural similarity (SSIM)~1.0000, near to 1.0000 is perfect
5Normalized Hamming distance (NHD)=1, equal to 1 is perfect