I think, that pixel to pixel comparison was done in some guides of doom9. So I assume, it's possible if you respect some given rules. But I think the average quantizer already gives you an idea about the image quality: the lower the avg quantizer, the closer to the original.

@DJ Bobo, The guides is about codec comparison if I was looking the same thing you said. I am talking a different thing. I am talking about a quantitative method to judge the quality of transcoded source. I use the following Avisynth script: LoadPlugin("C:\PROGRA~1\GORDIA~1\mpeg2dec.dll") Clip1 = mpeg2source("E:\MOVIES BUFFER\rush\rip.d2v").crop(4,72,712,430).BicubicResize(704,304,0,0.75).greyscale() Clip2 = Avisource("F:\Movies\movie.avi",false).greyscale() Subtract(clip1,clip2) Levels(127,1,129,0,255) There are 2 interesting facts with the above script. First, SUBTRACT adds "bias" 50% grey scale to the output. Second, the substratct's result is quite small in magnitude, almost invisible and mostly occured at the edge of an object (quantization effect). To make this visible, we need Levels(127,1,129,0,255) command to amplify the difference. Open this script in VDub (make sure you get the correct files with the same resolutions). The movie's artifacs are now visible.

That is really interesting, I like your idea.:D

8 KHz? you've gotta be kidding! if that's true, you've got damn bad bad ears. Most people can hear up to 16~17KHz. Younger people can hear up to 18~20KHz. During a test, I and some friend of mine were able to hear up to 22KHz (the test limit was 22KHz). May be I can hear more, if anyone knows a test that goes beyond 22KHz (say 24KHz), please tell me.

Indeed, And you are one of those guys with golden ears, I guess. :D The 8kHz is the -3dB cutt-off response. The peak is probably 5kHz (human voice). I still could hear 13 kHz but not as sensitive as in the lower frequency. I guess it is quite fine for fortiesh. By the way, MP3 probably is not for you. Should OGG's q > 10 ? :)

I don't know anymore, I found some wav file somewhere which frequency was changed continiously from 10 to 22KHz, and I was able to hear it to the very end, so I assume I can even hear beyond 22KHz ... Hmm .. I found it: BTW, I have a decent SONY stereo system, so I guess it's good enough for such tests isn't it? :D

its sad, I'm 16 and I got about 15khz on that test (good kilpsch speakers too) yah well, as long as I can still hear bass thats all that matters :/

Damn, only 17.2kHz. I dont know, maybe i can hear more (on studies i used to hear about 20Khz signal on osciloscope), but im 27 years old and probably aging have something to do there... :mad: :mad: :mad: Tought, my young years is not as good, as it maybe sounds, as i used to hear high pitches from TVs and such crap, what really bother me a lot... Now the TVsets are quiet, coz maybe means, that i lost my ability to hear them... OTOH, the audio system i have got is a real crap, its homemade by me, into 1992 from czech components, so, probably the two bands speakers and the homemade aplifier really cant get out of it more that 17kHz? Who knows, but hearing the 17,2kHz pitch hurt - not much, but a little... DJ Bobo - what for you? :rolleyes: :(