How to interpret PSNR value?

1. How do you interpret PSNR values?
2. What does high PSNR value mean?
3. How do I evaluate my PSNR?
4. What does a negative PSNR value mean?

How do you interpret PSNR values?

Typical values for the PSNR in lossy image and video compression are between 30 and 50 dB, provided the bit depth is 8 bits, where higher is better. The processing quality of 12-bit images is considered high when the PSNR value is 60 dB or higher. For 16-bit data typical values for the PSNR are between 60 and 80 dB.

What does high PSNR value mean?

The higher the PSNR, the better the quality of the compressed, or reconstructed image. The mean-square error (MSE) and the peak signal-to-noise ratio (PSNR) are used to compare image compression quality.

How do I evaluate my PSNR?

Express the PSNR in decibels. From Step 1, we have the decibel value LdB as LdB = 10 log10 (P1/P0). Now let P1 = MAX^2 and P0 = MSE. We then have PSNR = 10 log10(MAX^2/MSE) = 10 log10(MAX/(MSE)^(1/2))^2 = 20 log10(MAX/(MSE)^(1/2)).

What does a negative PSNR value mean?

If the MSE is very small, then you should most certainly get negative dB values for PSNR. It just means that the smoothing of the small-variance noise does much better than smoothing the noise with the higher variance.