Hello Jürgen,
> maybe you want to do some normalization on the image as a
> preprocessing step before actually doing the comparison?
Yes, perhaps a two-stage algorithm is the way to go. However, a
complete shift of the image might be an indication of a problem, too,
so in the end I want an algorithm that *reduces* the metric for such
cases but not eliminate it.
> In other scenarios, you may also want to normalize brightness /
> color / white balanve and other stuff,
I think we can safely ignore this for LilyPond.
Werner
