Re: search for better regtest comparison algorithm

2024-07-27 Thread Werner LEMBERG
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

Re: search for better regtest comparison algorithm

2024-07-27 Thread Luca Fascione
Ok awesome On Sat, 27 Jul 2024, 21:35 Werner LEMBERG, wrote: > > > Yes, I might be a moment due to friends visiting and such, but > > definitely can. > > Great! > > > Could you get me going pointing me to a few image pairs and an > > indication (like you did on SE) of the defect you see? > >

Re: search for better regtest comparison algorithm

2024-07-27 Thread Werner LEMBERG
> Yes, I might be a moment due to friends visiting and such, but > definitely can. Great! > Could you get me going pointing me to a few image pairs and an > indication (like you did on SE) of the defect you see? The example I gave on SE is *the* example – a small object of about the size of a

Re: search for better regtest comparison algorithm

2024-07-27 Thread Jürgen Reuter via Discussions on LilyPond development
Hi Werner, hi all, maybe you want to do some normalization on the image as a preprocessing step before actually doing the comparison? E.g. first crop the image, and then do the comparison. Of course, if there is even a _large_ shift, you will no more detect it at all after

Re: search for better regtest comparison algorithm

2024-07-27 Thread Luca Fascione
On Sat, Jul 27, 2024 at 8:18 PM Werner LEMBERG wrote: > Can you provide a demo? > Yes, I might be a moment due to friends visiting and such, but definitely can. Could you get me going pointing me to a few image pairs and an indication (like you did on SE) of the defect you see?

Re: search for better regtest comparison algorithm

2024-07-27 Thread Werner LEMBERG
> Werner the case you have on SE seems to indicate you need a > translation invariant test, I think. Whatever you say :-) Great that there are people on this list who can actually contribute to the topic. > In your case you could compute min diff over all possible > translations that would

Re: search for better regtest comparison algorithm

2024-07-27 Thread Luca Fascione
At my previous work I had written the image comparison framework for our regression test suite, it worked very well for us and it was in python/numpy/scipy (which threads well internally). Werner the case you have on SE seems to indicate you need a translation invariant test, I think. Another

Re: search for better regtest comparison algorithm

2024-07-27 Thread Han-Wen Nienhuys
FWIW, I wrote a version of the comparison in Go that does the entire comparison in-memory, without shelling out to any program. I did this because it parallelized much better (ie. is faster), but it also means you can easily test alternative algorithms. See here:

search for better regtest comparison algorithm

2024-07-27 Thread Werner LEMBERG
I've posted a question on StackExchange, searching for a better regtest comparison algorithm https://computergraphics.stackexchange.com/questions/14143/search-for-special-image-difference-metric Werner