Re: Resizing changes sharpness

[Jurian Sluiman <f-spot juriansluiman nl>]

Op zondag 29-07-2007 om 15:10 uur [tijdzone +0200], schreef Stephane Delcroix:
> Hi,
>
> Currently f-spot uses a bilinear algorithm to resize images. It's not
> the best in class, but it's quite good. But f-spot doesn't use any
> resharpening after resizing. And evaluating resizing capabilities of a
> photo software with a non-photo image is not really fair ;)
Funny, the pictures I uploaded were photos of a harbour in Dusseldorf (Germany), so it were no renders or something :p
> I can do some tests with an hyperbolic algorithm, and with some extra
> sharpening, but I'll need some eyes (and maybe some test pictures) to
> evaluate the results. In the meantime, can you send me your original
> test image ?
>
> regards
>
> s
I have uploaded three new photos, with quite more details than earlier. It's the trevi fountain in Rome:
http://download.juriansluiman.nl/fspot/trevi-fspot.jpg
http://download.juriansluiman.nl/fspot/trevi-flickr.jpg
http://download.juriansluiman.nl/fspot/trevi-original.jpg

These photos are full of small details, so you can see the differences easy. Thanks for your help.

Regards,
Jurian
> On Sun, 2007-07-29 at 12:42 +0200, Jurian Sluiman wrote:
> > Hi all,
> > I'm using f-spot for quite a time now, but every time I want to resize
> > a picture, the sharpness changes significantly. I compared the resizes
> > from f-spot, eog, gThumb and flickr, and it seems f-spot has the worst
> > resizing algorithm. To see the differences, compare these two
> > pictures:
> > http://download.juriansluiman.nl/fspot/fspot.jpg
> > http://download.juriansluiman.nl/fspot/flickr.jpg
> > 
> > It's clear the flickr resized picture is more sharpened than the fspot
> > one. I couldn't find anything about it on the wiki or the archives, so
> > I'm asking it here. I really like the program, all the features and
> > the usability. But the resizing problem struggles me. Is it possible
> > to fix it?
> > 
> > Thanks a lot, you're doing a great job ;)
> > 
> > Jurian Sluiman 
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