Ssim

[jigole]

Just a simple question: SSIM ranges between 0 and 1 but I have found in some threads that SSIM could range between 0 and 100. Can someone help? Whats is the right scale?
Thanks!!!

[Dark Shikari]

The latest SSIM filter used in Avisynth has a different scale than the original SSIM (which is the algorithm used in x264).

[jigole]

Thanks! I have find that SSIM can be scale by

100 * power(SIMM,8)

why is the formulae used?

[foxyshadis]

100 just gives it a nice percentage scale that people are more comfortable with. The power somewhat linearizes the scale vs. the raw values, because most people (again) aren't as comfortable with the exponential scale SSIM uses. (Especially since the asymptote is at 1, not 0.)

[jigole]

Thanks!