Talk:Peak signal-to-noise ratio

message: How is this different from regular SNR? — Omegatron 03:06, 1 December 2005 (UTC)

message: Similar to the SSIM page, I think the PSNR page should include information on variants such as PSNR-HVS and PSNR-HVS-M. There's not a ton of info on the web that explains these nicely so it'd be nice to have. I myself don't really have a great understanding on it so I can't write the part but I'm suggesting it as an addition.
PSNR-HVS: Peak Signal-to-Noise Ratio taking into account Contrast Sensitivity Function (CSF),
PSNR-HVS-M: Peak Signal-to-Noise Ratio taking into account Contrast Sensitivity Function (CSF) and between-coefficient contrast masking of DCT basis functions.
Sources for research: http://www.ponomarenko.info/psnrhvsm.htm Jiecut (talk) 18:38, 12 March 2016 (UTC)
thread_title: Variants

message: So is higher or lower PSNR better?  Can someone add this to the article?  Daniel.Cardenas 23:09, 7 August 2007 (UTC)
thread_title: simplify

message: Hello.
For "one-sided" signals such as Video/Luma I can see that the definition matches the equations; but for AC signals (such as Audio, which is signed, but also arguably Video/Chroma which is kinda unsigned) the definition of "peak energy" seems off by a factor of 2. Could some knowledgable author/editor clarify this please? Thanks. 212.44.20.129 (talk) 16:55, 19 June 2009 (UTC)
thread_title:  ac vs dc peak power 

message: This page says that the value of MAX is (2^B -1)
i have read (http://www.mathworks.com/matlabcentral/fileexchange/135-psnr) that the value of MAX is the max difference between the pixels of the two images. 
will the MAX for 16 bit images be 65535?
my images being 48 bit (3*16) I used 1/(m*n*3) to calculate MSE.
I am trying to convert an RGB image to YUV and convert the YUV back to RGB. so there is some loss introduced but not as much as a lossy compression. using Matlab's rgb2ycbcr and ycbcr2rgb functions, i was expecting a high PSNR value.
I was surprised to find that the PSNR was 100.1818, the MSE was 0.4118
but if I use 'max difference' as MAX i am getting 75.84 which seems to be more correct.
if use set MAX to 255+255/256 as specified in http://compression.ru/video/quality_measure/info_en.html#psnr I get 52.01 
please help me (ramprasad85 at gmail.com)
Ramprasad N (talk) 08:39, 11 August 2010 (UTC)
replies: text: It sounds like you have a colour image (3*16bit), rather than a high-depth greyscale (1*48bit). This makes a big difference! If a pixel value is 0xff0000, you should probably interpret that as 255/3 (mean intensity across colour channels), or something similar - not 16711680 (the 48 bit number, given in decimal). Your max range would then be 256, not 16777216. But don't take my word for it, I'm not an image processor, just thinking aloud ;-) GyroMagician (talk) 09:22, 11 August 2010 (UTC)
thread_title:  Confusion regarding the value of MAX used in PSNR calculation 

message: is there a reason for this? Is compression operating a hidden sharpening ?
If so it should be mentioned, if not the original may be wrong.  — Preceding unsigned comment added by Massimociacci (talk • contribs) 14:09, 26 October 2014 (UTC)
replies: text: Something somewhere is doing a very poor job of filtering the thumbnail that you see on the page.  The actual original in a lossless PNG file (click through to see), and all compressed files were derived from that original.  Yes, it's annoying and confusing. Weedwhacker128 (talk) 21:54, 26 October 2014 (UTC)
thread_title:  Original uncompressed image is much less sharp then compressed...