Editing Peak signal-to-noise ratio (section)

== Quality estimation with PSNR ==
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.

Typical values for the PSNR in [[lossy compression|lossy]] image and video compression are between 30 and 50&nbsp;dB, provided the bit depth is 8&nbsp;[[bit]]s, where higher is better. The processing quality of 12-bit images is considered high when the PSNR value is 60&nbsp;dB or higher.<ref>{{Cite journal|last1=Faragallah|first1=Osama S.|last2=El-Hoseny|first2=Heba|last3=El-Shafai|first3=Walid|last4=El-Rahman|first4=Wael Abd|last5=El-Sayed|first5=Hala S.|last6=El-Rabaie|first6=El-Sayed M.|last7=El-Samie|first7=Fathi E. Abd|last8=Geweid|first8=Gamal G. N.|date=2021|title=A Comprehensive Survey Analysis for Present Solutions of Medical Image Fusion and Future Directions|journal=IEEE Access|volume=9|pages=11358–11371|doi=10.1109/ACCESS.2020.3048315|issn=2169-3536|quote=This paper presents a survey study of medical imaging modalities and their characteristics. In addition, different medical image fusion approaches and their appropriate quality metrics are presented.|doi-access=free|bibcode=2021IEEEA...911358F }}</ref><ref>{{Cite journal|last1=Chervyakov|first1=Nikolay|last2=Lyakhov|first2=Pavel|last3=Nagornov|first3=Nikolay|date=2020-02-11|title=Analysis of the Quantization Noise in Discrete Wavelet Transform Filters for 3D Medical Imaging|journal=Applied Sciences|language=en|volume=10|issue=4|pages=1223|doi=10.3390/app10041223|issn=2076-3417|quote=The image processing quality is considered high if PSNR value is greater than 60 dB for images with 12 bits per color.|doi-access=free}}</ref> For 16-bit data typical values for the PSNR are between 60 and 80&nbsp;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=https://books.google.com/books?id=evGyv-mogukC&q=image%20compression%20acceptable%20PSNR&pg=PA156}}</ref><ref>{{cite book|author=Raouf Hamzaoui, Dietmar Saupe|title=Fractal Image Compression|journal=Document and Image Compression|date=May 2006|volume=968|pages=168–169|url=https://books.google.com/books?id=FmqPOsEYRsEC&q=image%20compression%20acceptable%20PSNR&pg=PA168|access-date=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>
The maximum PSNR for 8 bit is 48.131, for 10 bit is 60.198, for 12 bit is 72.245.

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 infinite (or 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=https://books.google.com/books?id=ujnQogzx_2EC&q=PSNR%20infinite&pg=PA281|edition=4|access-date=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
  }}