PSNR - Revision history

Raffriff42: tweak wording

2015-11-26T18:30:10Z

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2015-11-26T18:00:46Z

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2015-11-21T15:28:02Z

format inline math

Raffriff42: replace $with images generated @ Wikipedia$

2015-11-21T15:01:48Z

replace <math> with images generated @ Wikipedia

Admin: 1 revision

2013-05-09T21:34:06Z

1 revision

Wilbert: typo

2008-06-07T12:16:42Z

typo

New page

PSNR is measured in decibels. It's defined as

<math>PSNR(I,K) = 20 \cdot \log_{10}{(\frac{255}{\sqrt{MSE(I,K)}})}</math>

with

<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 <tt>M</tt> = <tt>width</tt> <math>\cdot</math> <tt>height</tt> is the number of pixels in a frame and <tt>width</tt>, <tt>height</tt> are the width and height of the frame, respectively, in pixels.

The double-sum term states that <tt>(j,k)</tt> runs over all pixels of the frame, summing the absolute value of the difference of I, K functions raised to the power of 2.

For more details see: http://en.wikipedia.org/wiki/PSNR .

[[Category:Glossary]]

@@ Line 6: / Line 6: @@
 [[File:PSNR_Eq2.png|x48px|<math>MSE(I,K) = \frac{1}{M} \cdot \sum_{j=0}^{width-1} \sum_{k=0}^{height-1} &#124; I(j,k) - K(j,k) &#124;^{2}</math>]]
-The double-{{Serif|Σ}} term states that {{Serif|(''j'',''k'')}} runs over all pixels of the frame, summing the squared absolute value of the difference between reference image {{Serif|''I''}} and test image {{Serif|''K''}}.
+Where ''{{Serif|M}} ''is the number of pixels in a frame ({{Serif|''width''}} '''&middot;''' {{Serif|''height''}})
 '''External Links'''

@@ Line 1: / Line 1: @@
-PSNR is measured in decibels. It's defined as
+'''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|x40|<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:
-with
+[[File:PSNR_Eq2.png|x48px|<math>MSE(I,K) = \frac{1}{M} \cdot \sum_{j=0}^{width-1} \sum_{k=0}^{height-1} &#124; I(j,k) - K(j,k) &#124;^{2}</math>]]
-[[File:PSNR_Eq2.png|x40|<math>MSE(I,K) = \frac{1}{M} \cdot \sum_{j=0}^{width-1} \sum_{k=0}^{height-1} &#124; I(j,k) - K(j,k) &#124;^{2}</math>]]
+The double-{{Serif|Σ}} term states that {{Serif|(''j'',''k'')}} runs over all pixels of the frame, summing the squared absolute value of the difference between reference image {{Serif|''I''}} and test image {{Serif|''K''}}.
-where ''{{Serif|M}} = {{Serif|width}} '''&middot;''' {{Serif|height}}'' is the number of pixels in a frame and {{Serif|''width''}}, {{Serif|''height''}} are the width and height of the frame, respectively, in pixels.
+'''External Links'''
+* For more details see [http://en.wikipedia.org/wiki/PSNR wikipedia:PSNR].
-The double-sum term states that {{Serif|(''j'',''k'')}} runs over all pixels of the frame, summing the absolute value of the difference of {{Serif|''I, K''}} functions raised to the power of 2.
+* 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.
-For more details see: http://en.wikipedia.org/wiki/PSNR .
 [[Category:Glossary]]

@@ Line 7: / Line 7: @@
 [[File:PSNR_Eq2.png|x40|<math>MSE(I,K) = \frac{1}{M} \cdot \sum_{j=0}^{width-1} \sum_{k=0}^{height-1} &#124; I(j,k) - K(j,k) &#124;^{2}</math>]]
-where <tt>M</tt> = <tt>width</tt> '''&middot;''' <tt>height</tt> is the number of pixels in a frame and <tt>width</tt>, <tt>height</tt> are the width and height of the frame, respectively, in pixels.
+where ''{{Serif|M}} = {{Serif|width}} '''&middot;''' {{Serif|height}}'' is the number of pixels in a frame and {{Serif|''width''}}, {{Serif|''height''}} are the width and height of the frame, respectively, in pixels.
-The double-sum term states that <tt>(j,k)</tt> runs over all pixels of the frame, summing the absolute value of the difference of I, K functions raised to the power of 2.
+The double-sum term states that {{Serif|(''j'',''k'')}} runs over all pixels of the frame, summing the absolute value of the difference of {{Serif|''I, K''}} functions raised to the power of 2.
 For more details see: http://en.wikipedia.org/wiki/PSNR .
 [[Category:Glossary]]

PSNR - Revision history

Raffriff42: tweak wording

Raffriff42: tweak wording

Raffriff42: format inline math

Raffriff42: replace with images generated @ Wikipedia

Admin: 1 revision

Wilbert: typo

Raffriff42: replace $with images generated @ Wikipedia$