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oversharpening
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3e
says:
Flickr staff, what's going on with regards to oversharpening problems. I've done quite a bit of my own testing, and Flickr's resized images are really way, way worse than anything Photoshop, netpbm, imagemagick, or even the standard image libraries in Matlab produce. What's happening?
Posted at 2:53PM, 15 August 2005 PDT
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S'funny, because we use ImageMagick ;)
(Actually GraphicsMagick, which is a branch off the ImageMagick tree.)
Nothing has changed lately, so I wouldn't really say this is a bug: just that you don't like the results :)
We have to tweak the settings for a huge variety of users/conditions/photos, so it definitely won't always produce great results for particular images -- this is especially true if you sharpen an image a lot before uploading it.
However, we are testing settings to see if we can produce better results across a wide variety of source files and still remain in the same file size range.
Posted 83 months ago.
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3e
says:
Thanks for that info. The note about sharpening before uploading might be especially useful - I have a feeling the person who asked me to complain about this uses quite a bit of fancy sharpening algorithms on her photos.
FWIW - before this was brought to my attention I hadn't even noticed it. It's a friend of mine (who has over ten thousand photos and is deciding between Flickr and Smugmug) who said "hey, I want to use Flickr, but I can't because of this sharpening issue."
Posted 82 months ago.
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3e
says:
Quoting my friend's response, here:
My thoughts? Well, it seems that Flickr's goal is to create small
images (in terms of kb) in order to keep the load on their servers
down. My response to that is - the flickr-resized image of the girl at
500 px is 30.6 KB, whereas the same gallery-resized image is 30.7 KB.
In my opinion, they can certainly spare that much space for a vast
improvement in image quality.
I think the actual problem is coming from setting the JPEG quality too low. There are pretty bad JPEG artifacts in all of Flickr's resized images, and
that just shouldn't be happening. This would also make sense if
they're using ImageMagick but just setting the quality lower. Also,
from looking at the two images of the girl in Photoshop, I can see
that the gallery-resized one is 72 ppi (web resolution) and the
flickr-resized one is 180 ppi (the original resolution). I don't know
why that would cause the image to look worse, and maybe it doesn't,
but there it is.
We have to tweak the settings for a huge variety of users/conditions/
photos, so it definitely won't always produce great results for
particular images -- this is especially true if you sharpen an
image a lot before uploading it.
Well, gallery's method produces better results for pretty much
everything I've ever looked at. And by 'better' I mean 'closest to the
original,' which is the only measure of 'better' they should be using
for comparison. Some people said that the picture of the girl looked
better when Flickr resized it because it was sharper and brighter. To
which I say, but the original wasn't!
Similarly, yes, it is possible to oversharpen the original of an
image. But I (and most people) don't do that. When I sharpen, it makes
the original look crisp yet natural - but a crisp original looks
oversharpened in Flickr, whereas a slightly blurry original looks
crisp in Flickr. So Stewart's response seems to be telling me two
things: 1) his assumption is that "sharpening a lot" is always
oversharpening, which just isn't true, and 2) to make my original
slightly blurry so that it'll look crisp in Flickr. Well, that's just
going about things backwards. The service should cater to the photo,
not the photo to the service.
Anyway, I don't mean to be quite so militant about this issue, but it
boggles me how the staff don't see the problem. Boiled down, my stance
is "the resized version should be as true to the original as
possible." Gallery's use of Imagemagick does that, Flickr's use of it doesn't.
Posted 82 months ago.
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...by 'better' I mean 'closest to the original,' which is the only measure of 'better' they should be using for comparison.
...it boggles me how the staff don't see the problem. Boiled down, my stance is "the resized version should be as true to the original as possible."
For a serious photographer, yes.
For the average Flickr user, who posts family snaps and the occasional cameraphone shot, sharper is better.
I can guarantee that if Flickr reduced the sharpening, they would hear plenty of complaints from other users who preferred the old level of sharpening. I think it's a case of your friend, not Flickr staff, not seeing the problem.
You just can't please all the users all the time.
Posted 82 months ago.
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3e
says:
Maybe this could be a preference people could select?
Posted 82 months ago.
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This thread was closed automatically due of a lack of responses over the last month.
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