PSNR

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PSNR is measured in decibels. It's defined as
 
PSNR is measured in decibels. It's defined as
  
<math>PSNR(I,K) = 20 \cdot \log_{10}{(\frac{255}{\sqrt{MSE(I,K)}})}</math>
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[[File:PSNR_Eq1.png|x40|<math>PSNR(I,K) = 20 \cdot \log_{10}{(\frac{255}{\sqrt{MSE(I,K)}})}</math>]]
  
 
with
 
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>
+
[[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> <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.  
+
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.  
  
 
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 <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.

Revision as of 17:01, 21 November 2015

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 M = width · height is the number of pixels in a frame and width, height are the width and height of the frame, respectively, in pixels.

The double-sum term states that (j,k) 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 .

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