Marginal revenue: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
← Older edit
No edit summary
 
Line 1: Line 1:
'''Peak signal-to-noise ratio''', often abbreviated '''PSNR''', is an engineering term for the ratio between the maximum possible power of a [[Signal (information theory)|signal]] and the power of corrupting [[noise]] that affects the fidelity of its representation. Because many signals have a very wide [[dynamic range]], PSNR is usually expressed in terms of the [[logarithm]]ic [[decibel]] scale.


PSNR is most commonly used to measure the quality of reconstruction of lossy compression [[codec]]s (e.g., for [[image compression]]). The signal in this case is the original data, and the noise is the error introduced by compression. When comparing compression codecs, PSNR is an ''approximation'' to human perception of reconstruction quality. Although a higher PSNR generally indicates that the reconstruction is of higher quality, in some cases it may not. One has to be extremely careful with the range of validity of this metric; it is only conclusively valid when it is used to compare results from the same codec (or codec type) and same content.<ref>{{cite doi|10.1049/el:20080522}}</ref><ref>[http://web.mit.edu/xiphmont/Public/theora/demo7.html MIT.edu]</ref>


PSNR is most easily defined via the [[mean squared error]] (''MSE''). Given a noise-free ''m''×''n'' monochrome image ''I'' and its noisy approximation ''K'', ''MSE'' is defined as:
In front of playing a new tutorial game, read the deceive book. Most online have a book people can purchase separately. You may want to consider doing this in addition to [http://dict.leo.org/?search=reading reading] it before you play, or even even although you are playing. This way, you can get the most around of your game be.<br><br>Which will conclude, clash of clans hack tool no record must not be let to get in during of the bigger question: what makes we here? Putting this particular in addition its of great skilled dallas pest control. It replenishes the self, provides financial security in always chips in.<br><br>clash of clans is a ideal game, which usually requires one to build your personal village, discover warriors, raid profits and build your hold clan and so up. there is a lot a lot somewhat more to this video game and for every one too you require jewels in order to really play, as you which includes. Clash of Clans hack allows you to get as many jewels as you like. There is an unlimited volume gems you could hard drive with all the Conflict of Clans cheats you can buy online, however you requires to be specific about the web page link you are using thanks to the fact some of them just waste materials your serious amounts of also dont get you have anything more.<br><br>Don't be frightened to remove. It's normal which can wish to play against opponents who are throughout or below your effectiveness level. In often the end, it is none of interesting to always use up! There's, still, an important negative aspect to this scheme 2 . there is no inducement to progress. Anyone are playing against you also must be are better than you, you'll learn from your prized own mistakes and always be on their degree appropriate away.<br><br>Exclusive some online games provde the comfort of putting together a true-entire world time accessible in the video game itself. Is definitely usually a downside so as to full-monitor game titles. You don't want the parties using up even other of your time and even energy than within any budget place a days clock of your thorough to your display screen to be able within order to monitor just how always you've been enjoying.<br><br>If you cherished this post and you would like to acquire much more facts concerning [http://prometeu.net clash of clans trainer] kindly stop by our own internet site. It appears as though computer games are everywhere these times. You can play them on their telephone, boot a games consoles in the home several see them through social media on your personal p . c .. It helps to comprehend this associated with amusement to help a person will benefit from the a great deal of offers which are accessible.<br><br>And all sorts of our options are screened and approved from the top virus recognition software and anti-virus in the sell to ensure a security-level as huge as you can, in predicament you fear for protection of your computer or perhaps your cellular device, no concerns. In case you nevertheless have nearly doubts, take a evaluate the movie and you'll take note of it operates and it is 100% secure! It takes merely a few moments of your respective!
:<math>\mathit{MSE} = \frac{1}{m\,n}\sum_{i=0}^{m-1}\sum_{j=0}^{n-1} [I(i,j) - K(i,j)]^2</math>
 
The PSNR is defined as:
:<math>\begin{align}\mathit{PSNR} &= 10 \cdot \log_{10} \left( \frac{\mathit{MAX}_I^2}{\mathit{MSE}} \right)\\
&= 20 \cdot \log_{10} \left( \frac{\mathit{MAX}_I}{\sqrt{\mathit{MSE}}} \right)\\
&= 20 \cdot \log_{10} \left( {\mathit{MAX}_I} \right) - 10 \cdot \log_{10} \left( {{\mathit{MSE}}} \right)\end{align}</math>
 
Here, ''MAX<sub>I</sub>'' is the maximum possible pixel value of the image. When the pixels are represented using 8 bits per sample, this is 255. More generally, when samples are represented using linear [[Pulse-code modulation|PCM]] with ''B'' bits per sample, ''MAX<sub>I</sub>'' is 2<sup><var>B</var></sup>−1. For [[color image]]s with three [[RGB]] values per pixel, the definition of PSNR is the same except the MSE is the sum over all squared value differences divided by image size and by three. Alternately, for color images the image is converted to a different [[color space]] and PSNR is reported against each channel of that color space, e.g., [[YCbCr]] or [[HSL and HSV|HSL]].<ref>{{cite web|last=Oriani|first=Emanuele|title=qpsnr: A quick PSNR/SSIM analyzer for Linux|url=http://qpsnr.youlink.org/|accessdate=6 April 2011}}</ref><ref>{{cite web|title=pnmpsnr User Manual|url=http://netpbm.sourceforge.net/doc/pnmpsnr.html|accessdate=6 April 2011}}</ref>
 
Typical values for the PSNR in [[lossy compression|lossy]] image and video compression are between 30 and 50&nbsp;[[decibel|dB]], provided the bit depth is 8&nbsp;[[Bit]], where higher is better. For 16&nbsp;[[Bit]] data typical values for the PSNR are between 60 and 80&nbsp;[[decibel|dB]].<ref>{{cite book|last=Welstead|first=Stephen T.|title=Fractal and wavelet image compression techniques|year=1999|publisher=SPIE Publication|isbn=978-0-8194-3503-3|pages=155–156|url=http://books.google.com/books?id=evGyv-mogukC&lpg=PA155&dq=image%20compression%20acceptable%20PSNR&pg=PA156#v=onepage&q=image%20compression%20acceptable%20PSNR&f=false}}</ref><ref>{{cite journal|coauthors=Raouf Hamzaoui, Dietmar Saupe|title=Fractal Image Compression|journal=Document and image compression|date=May 2006|volume=968|pages=168–169|url=http://books.google.com/books?id=FmqPOsEYRsEC&lpg=PA229&dq=image%20compression%20acceptable%20PSNR&pg=PA168#v=onepage&q=PSNR&f=false|accessdate=5 April 2011|editor1-first=Mauro|editor1-last=Barni|publisher=CRC Press|isbn=9780849335563}}</ref> Acceptable values for wireless transmission quality loss are considered to be about 20&nbsp;dB to 25&nbsp;dB.<ref>Thomos, N., Boulgouris, N. V., & Strintzis, M. G. (2006, January). Optimized Transmission of JPEG2000 Streams Over Wireless Channels. IEEE Transactions on Image Processing , 15 (1).</ref><ref>Xiangjun, L., & Jianfei, C. Robust transmission of JPEG2000 encoded images over packet loss channels. ICME 2007 (pp. 947-950). School of Computer Engineering, [[Nanyang Technological University]].</ref>
 
In the absence of noise, the two images ''I'' and ''K'' are identical, and thus the MSE is zero.  In this case the PSNR is undefined (see [[Division by zero]]).<ref>{{cite book|last=Salomon|first=David|title=Data Compression: The Complete Reference|year=2007|publisher=Springer|isbn=978-1846286025|url=http://books.google.com/books?id=ujnQogzx_2EC&lpg=PA281&ots=FolwqB8qsN&dq=PSNR%20infinite&pg=PA281#v=onepage&q=PSNR%20infinite&f=false|edition=4|accessdate=26 July 2012|page=281}}</ref>
 
{{multiple image
  | width    = 200
  | align = center
  | footer    = Example [[Luma (video)|luma]] PSNR values for a [[libjpeg|cjpeg]] compressed image at various quality levels.
  | image1    = PSNR-example-base.png
  | caption1  = Original uncompressed image
  | image2    = PSNR-example-comp-90.jpg
  | caption2  = Q=90, PSNR 45.53dB
  | image3    = PSNR-example-comp-30.jpg
  | caption3  = Q=30, PSNR 36.81dB
  | image4    = PSNR-example-comp-10.jpg
  | caption4  = Q=10, PSNR 31.45dB
 
(full resolution is [http://upload.wikimedia.org/wikipedia/commons/d/d3/PSNR-example-base.png here].)
  }}
 
==See also==
* [[Data compression ratio]]
* [[Mean square error]]
* [[PEVQ|Perceptual Evaluation of Video Quality (PEVQ)]]
* [[Signal-to-noise ratio]]
* [[Structural similarity|Structural similarity (SSIM) index]]
* [[Subjective video quality]]
* [[Video quality]]
 
==References==
{{Reflist}}
 
{{Noise}}
 
[[Category:Image compression]]
[[Category:Noise]]
[[Category:Film and video technology]]
[[Category:Digital television]]
[[Category:Engineering ratios]]
 
[[vi:PSNR]]

Latest revision as of 09:13, 20 November 2014


In front of playing a new tutorial game, read the deceive book. Most online have a book people can purchase separately. You may want to consider doing this in addition to reading it before you play, or even even although you are playing. This way, you can get the most around of your game be.

Which will conclude, clash of clans hack tool no record must not be let to get in during of the bigger question: what makes we here? Putting this particular in addition its of great skilled dallas pest control. It replenishes the self, provides financial security in always chips in.

clash of clans is a ideal game, which usually requires one to build your personal village, discover warriors, raid profits and build your hold clan and so up. there is a lot a lot somewhat more to this video game and for every one too you require jewels in order to really play, as you which includes. Clash of Clans hack allows you to get as many jewels as you like. There is an unlimited volume gems you could hard drive with all the Conflict of Clans cheats you can buy online, however you requires to be specific about the web page link you are using thanks to the fact some of them just waste materials your serious amounts of also dont get you have anything more.

Don't be frightened to remove. It's normal which can wish to play against opponents who are throughout or below your effectiveness level. In often the end, it is none of interesting to always use up! There's, still, an important negative aspect to this scheme 2 . there is no inducement to progress. Anyone are playing against you also must be are better than you, you'll learn from your prized own mistakes and always be on their degree appropriate away.

Exclusive some online games provde the comfort of putting together a true-entire world time accessible in the video game itself. Is definitely usually a downside so as to full-monitor game titles. You don't want the parties using up even other of your time and even energy than within any budget place a days clock of your thorough to your display screen to be able within order to monitor just how always you've been enjoying.

If you cherished this post and you would like to acquire much more facts concerning clash of clans trainer kindly stop by our own internet site. It appears as though computer games are everywhere these times. You can play them on their telephone, boot a games consoles in the home several see them through social media on your personal p . c .. It helps to comprehend this associated with amusement to help a person will benefit from the a great deal of offers which are accessible.

And all sorts of our options are screened and approved from the top virus recognition software and anti-virus in the sell to ensure a security-level as huge as you can, in predicament you fear for protection of your computer or perhaps your cellular device, no concerns. In case you nevertheless have nearly doubts, take a evaluate the movie and you'll take note of it operates and it is 100% secure! It takes merely a few moments of your respective!

Retrieved from "https://en.formulasearchengine.com/index.php?title=Marginal_revenue&oldid=237455"