PSNR
From Avisynth wiki
(Difference between revisions)
(typo) |
Raffriff42 (Talk | contribs) m (tweak wording) |
||
| (4 intermediate revisions by 2 users not shown) | |||
| Line 1: | Line 1: | ||
| − | PSNR is | + | '''PSNR''' stands for '''P'''eak '''S'''ignal-to-'''N'''oise '''R'''atio. It is used as a measure of [http://en.wikipedia.org/wiki/Video_quality video quality]. It is expressed in [[wikipedia:Decibel|decibels]]. It's defined as |
| + | [[File:PSNR_Eq1.png|x48px|<math>PSNR(I,K) = 20 \cdot \log_{10}{(\frac{255}{\sqrt{MSE(I,K)}})}</math>]] | ||
| − | + | where ''{{Serif|I}} ''is the reference image, ''{{Serif|K}} ''is the image under test, and ''{{Serif|MSE}} ''is the [http://en.wikipedia.org/wiki/Mean_squared_error Mean Squared Error] between the two: | |
| − | + | [[File:PSNR_Eq2.png|x48px|<math>MSE(I,K) = \frac{1}{M} \cdot \sum_{j=0}^{width-1} \sum_{k=0}^{height-1} | I(j,k) - K(j,k) |^{2}</math>]] | |
| − | + | Where ''{{Serif|M}} ''is the number of pixels in a frame ({{Serif|''width''}} '''·''' {{Serif|''height''}}) | |
| − | + | The double-{{Serif|Σ}} term states that {{Serif|(''j'',''k'')}} runs over all the pixels, summing the square of the difference between reference image {{Serif|''I''}} and test image {{Serif|''K''}}. | |
| − | + | '''External Links''' | |
| − | + | * For more details see [http://en.wikipedia.org/wiki/PSNR wikipedia:PSNR]. | |
| − | For more details see | + | * See also, [http://en.wikipedia.org/wiki/Structural_similarity wikipedia:SSIM] (Structural SIMilarity), another widely-used quality measure. |
| + | * See also, [http://en.wikipedia.org/wiki/Video_quality wikipedia:Video Quality] for a discussion of the difficulties involved in trying to make an "objective" quality measurement. | ||
[[Category:Glossary]] | [[Category:Glossary]] | ||
Latest revision as of 20:30, 26 November 2015
PSNR stands for Peak Signal-to-Noise Ratio. It is used as a measure of video quality. It is expressed in decibels. It's defined as
where I is the reference image, K is the image under test, and MSE is the Mean Squared Error between the two:
Where M is the number of pixels in a frame (width · height)
The double-Σ term states that (j,k) runs over all the pixels, summing the square of the difference between reference image I and test image K.
External Links
- For more details see wikipedia:PSNR.
- See also, wikipedia:SSIM (Structural SIMilarity), another widely-used quality measure.
- See also, wikipedia:Video Quality for a discussion of the difficulties involved in trying to make an "objective" quality measurement.
