similar image search not always working as expected

[Daniel Bauer]

Hello,

Sometimes similar image search does not show all possible results, even 
though I use similarity 55 - 100%. It does find it though with 
similarity set to 40%, but then of course it also finds a lot of false 
positives.

Besides of file format and size the two images are identical, actually 
the image used for the search is just a smaller .jpg-version made from 
the .png original with a small added watermark.

Over this night I let digikam rebuild all "fingerprints", but even after 
a restart of dk if doesn't find those images when set to 50 or 55%.

Is there a problem with .png files? (although it happens only with few 
images, other .png's of other images are found)
Can I better the results with any trick?

I can provide access to sample images in private, but those are nudes...

Kind regards

Daniel

(I often use this function to find the original file or a published 
version without having to go through the albums with countless photos, 
even more when I forgot the name of a model :-) )
-- 
Daniel Bauer photographer Basel Málaga
Twitter: @Marsfotografo (often explicit nudes)
https://www.patreon.com/danielbauer
https://www.daniel-bauer.com (nudes)