I tried File:Rajpoots_2.png, a 10MP engraving scan which is a subject of
bug 24889 about Moiré patterns:
<https://commons.wikimedia.org/wiki/File:Rajpoots_2.png>
<https://bugzilla.wikimedia.org/show_bug.cgi?id=24889>

At the given default settings I think it does a better job than current
ImageMagick, while still not perfect:
<
https://test2.wikipedia.org/wiki/Special:VipsTest?file=Rajpoots_2.png&width=310&sharpen=0.8
>
<
https://test2.wikipedia.org/wiki/Special:VipsTest?file=Rajpoots_2.png&width=640&sharpen=0.8
>

The sharpening makes the image "pop" a little nicely, but the Moiré pattern
is (somewhat) reduced regardless of that setting. Still not nearly as nice
as a non-decimated scale down with ImageMagick (which we don't use).

Enabling bilinear filtering causes HUGE HORRIBLE artifacts, and is
definitely not a good thing for that sort of image. :)
<
https://test2.wikipedia.org/wiki/Special:VipsTest?file=Rajpoots_2.png&width=310&sharpen=0.8&bilinear=1
>
<
https://test2.wikipedia.org/wiki/Special:VipsTest?file=Rajpoots_2.png&width=640&sharpen=0.8&bilinear=1
>

-- brion
_______________________________________________
Wikitech-l mailing list
[email protected]
https://lists.wikimedia.org/mailman/listinfo/wikitech-l

Reply via email to