wegge wrote:

If the image should be sharpened in any particular resolution, the uploader
should do that manually. An automatic action on all images will produce shitty
results in a few cases, without editors having a chance of finding out why. I
feel inclined to WONTFIX this right away.

klee wrote:

In other words, you prefer to optimize for the uncommon case, rather than the common case.

interesting, can anyone provide with a gallery of examples? :)

• Bug 7383 has been marked as a duplicate of this bug. ***

(in replay to comment #1)

If the image should be sharpened in any particular resolution, the uploader
should do that manually. An automatic action on all images will produce shitty
results in a few cases

The full size uploaded image has to be as sharp as possible. But please believe
me, if you scale down an image you has to resharpen it for a better look.

(In reply to comment #3)

interesting, can anyone provide with a gallery of examples? :)

Please see example at bug 7383.

If possible by the used libs, please add a little bit sharpness to the generated
thumbs. The actual generated thumbs are to blurry even though the original full
size uploaded image is really sharp.

ejsanders wrote:

Copying that example here:
Compare
http://upload.wikimedia.org/wikipedia/commons/thumb/a/a5/Champions_League_trophy.jpg/375px-Champions_League_trophy.jpg
with
http://static.flickr.com/95/224894467_8f0e771cce.jpg

So Flickr are obviously use sharpening to good effect.

addicks wrote:

I would really appreciate automatic sharpening for thumbnails PLUS more quality for
thumbnails.
The quality of the thumbnails generated by mediawiki are o.k. for "old CRTs on bad VGA-
cabling", and for lowres uploads. but the higher the resolution of the uploaded images, the
worse the thumbs/scalings become.

As you ask for examples, to visualize the need for this function

a) Sharpeining for Thumbs
Please compare
-Raw Image "sharp, "uploaded in hires"
http://upload.wikimedia.org/wikipedia/de/d/d6/K%C3%B6nigsallee_in_D%C3%BCsseldorf_Girardetbr%
C3%BCcke_bei_Nacht.jpg

-Raw Image "sharpened" "low resolution upload"
http://upload.wikimedia.org/wikipedia/commons/1/1a/Koenigsallee_okt2004.jpg

In the article the thumb of the lowres-picture looks brilliant, but the thumb of the hires is
really ugly.

http://upload.wikimedia.org/wikipedia/de/thumb/d/d6/K%C3%B6nigsallee_in_D%C3%
BCsseldorf_Girardetbr%C3%BCcke_bei_Nacht.jpg/300px-K%C3%B6nigsallee_in_D%C3%
BCsseldorf_Girardetbr%C3%BCcke_bei_Nacht.jpg
and compare to
http://upload.wikimedia.org/wikipedia/commons/thumb/1/1a/Koenigsallee_okt2004.jpg/300px-
Koenigsallee_okt2004.jpg

Or on drawings:
Fulres:
http://upload.wikimedia.org/wikipedia/commons/c/ce/Schwarzplan_Tausendfuessler.jpg
thumb:
http://upload.wikimedia.org/wikipedia/commons/thumb/c/ce/Schwarzplan_Tausendfuessler.jpg/200px-
Schwarzplan_Tausendfuessler.jpg

b) More q (quality) for thumgs
there are often very disturbing artefacts on the thumbnails

have a look at the Tomatoe-Images
original:
http://upload.wikimedia.org/wikipedia/commons/d/d2/Tomatoes_plain_and_sliced.jpg

thumb:
http://upload.wikimedia.org/wikipedia/commons/thumb/d/d2/Tomatoes_plain_and_sliced.jpg/250px-
Tomatoes_plain_and_sliced.jpg

-jha-

addicks wrote:

I would really appreciate automatic sharpening for thumbnails PLUS more quality for thumbnails.
The quality of the thumbnails generated by mediawiki are o.k. for "old CRTs on bad VGA-cabling",
and for lowres uploads. but the higher the resolution of the uploaded images, the worse the
thumbs/scalings become.

As you ask for examples, to visualize the need for this function

a) Sharpeining for Thumbs
Please compare
-Raw Image "sharp, "uploaded in hires"
http://upload.wikimedia.org/wikipedia/de/d/d6/K%C3%B6nigsallee_in_D%C3%BCsseldorf_Girardetbr%C3%
BCcke_bei_Nacht.jpg

-Raw Image "sharpened" "low resolution upload"
http://upload.wikimedia.org/wikipedia/commons/1/1a/Koenigsallee_okt2004.jpg

In the article the thumb of the lowres-picture looks brilliant, but the thumb of the hires is
really ugly.

http://upload.wikimedia.org/wikipedia/de/thumb/d/d6/K%C3%B6nigsallee_in_D%C3%
BCsseldorf_Girardetbr%C3%BCcke_bei_Nacht.jpg/300px-K%C3%B6nigsallee_in_D%C3%
BCsseldorf_Girardetbr%C3%BCcke_bei_Nacht.jpg
and compare to
http://upload.wikimedia.org/wikipedia/commons/thumb/1/1a/Koenigsallee_okt2004.jpg/300px-
Koenigsallee_okt2004.jpg

Or on drawings:
Fulres:
http://upload.wikimedia.org/wikipedia/commons/c/ce/Schwarzplan_Tausendfuessler.jpg
thumb:
http://upload.wikimedia.org/wikipedia/commons/thumb/c/ce/Schwarzplan_Tausendfuessler.jpg/200px-
Schwarzplan_Tausendfuessler.jpg

b) More q (quality) for thumgs
there are often very disturbing artefacts on the thumbnails

have a look at the Tomatoe-Images
original:
http://upload.wikimedia.org/wikipedia/commons/d/d2/Tomatoes_plain_and_sliced.jpg

thumb:
http://upload.wikimedia.org/wikipedia/commons/thumb/d/d2/Tomatoes_plain_and_sliced.jpg/250px-
Tomatoes_plain_and_sliced.jpg

-jha-

(In reply to comment #3)

interesting, can anyone provide with a gallery of examples? :)

I've made an example here:

http://de.wikipedia.org/wiki/Benutzer:Smial/thumbtest

Comments are welcome

smial

(In reply to comment #9)

(In reply to comment #3)

interesting, can anyone provide with a gallery of examples? :)

Please visit
http://www.smial.prima.de/bilderwerkstatt/thumbtest/wikimedia_thumbtest.html
Six examples for different values for the "convert" command.
Comments or questions welcome here:
http://de.wikipedia.org/wiki/Benutzer_Diskussion:Smial/thumbtest
In short:
convert "input file" -thumbnail %sizex -sharpen 0x0.8 "output file"
should be a useful compromise for either small thumbs down to 120px or previews
at least up to 800x600px.
smial

Fixed with r21411 by Tim Starling. Thanks a lot!

See also Bug 24857 (sharpening affected by ImageMagick update).