About "Compare" filter

[Alex_e_Basta]

I tried to use this filter to determine psnr and I got very good results indeed. I compared a clip I encoded at 720x296 with the original resized at 720x296 and a second clip at 640x264 with the same original clip resized at 640x264: my 2 scripts

LoadPlugin("C:\Avisynth\mpeg2dec.dll")
orig=mpeg2source("C:\Avisynth\Prove\PA.d2v").crop(3,74,713,427).BicubicResize(720,296,0,0.75)
encoded=avisource("C:\Avisynth\Prove\PA Divx 720x296 SharpBicubic.avi")
compare(encoded,orig,"","C:\Avisynth\Prove\PA Divx 720x296 SharpBicubic.txt",False)

LoadPlugin("C:\Avisynth\mpeg2dec.dll")
orig=mpeg2source("C:\Avisynth\Prove\PA.d2v").crop(3,74,713,427).BicubicResize(640,264,0,0.75)
encoded=avisource("C:\Avisynth\Prove\PA Divx 640X264 SharpBicubic.avi")
compare(encoded,orig,"","C:\Avisynth\Prove\PA Divx 640X264 SharpBicubic.txt",False)

Now a question: can I compare the avg psnr of the clip at 720x296 with the avg psnr at 640x264 to determine which clip has the *better* quality ?

[tenebrenz]

Now a question: can I compare the avg psnr of the clip at 720x296 with the avg psnr at 640x264 to determine which clip has the best quality ?
I don't think so, the lower res encode should have less noise as there are more bits per pixel so therefore should match the downsized original more closely.
To find out which encode is technically *better* I think you would have to resize your encodes up to source resolution and see which one matches the source closer.