Compression on Uploaded Photos

[Bruce]

When I compare the database version with the one I uploaded from my computer, I can see some degrading of the image. Looks like jpeg compression to me. It kind of makes some of the photos look worse when viewed online. Has anyone else noticed this?

[Leftseat86]

Compression on Uploaded Photos

Thank you Bruce!!!! I thought I was the only one noticing this. I get the same thing you described.


-Clovis [img]nod.gif[/img]

[Chris Kilroy]

Compression on Uploaded Photos

Guys,

That's interesting, since we are not actually applying any compression to uploaded photos.

When a photo is uploaded, it is first resized to 200px wide, sharpened 10%, and saved as a thumbnail. The large photo is then reduced to 1024px if larger, an image of the same width of the original photo is created, the copyright added to that image, and the newly created copyright bar appended to the large image.

That's it.

I'm at a loss as to what could be causing a loss of quality.

[Chris Kilroy]

Compression on Uploaded Photos

Here, by the way, is the code which does all this -- just so you guys know I'm not making it up. [img]images/smiles/icon_biggrin.gif[/img]

[Bruce]

Compression on Uploaded Photos

Chris,

It looks as if the images are re-sized to 1024x1024 and then sharpened 20. I think that may be the cause of it. If I sharpen an image 20% in photoshop, after its been optimized using USM etc then it will appear oversharpened, just a bit. The "compression" that I'm seeing may not be compression at all but rather a tad oversharpened.

I wonder, why is it important for your script to sharpen the image?

[Chris Kilroy]

Compression on Uploaded Photos

Bruce,

The script resizes an image to 1024px and adds sharpening ONLY if the image was above 1024px when uploaded. The reason for the sharpening when an image is reduced in size is, as you know, an image reduced in size tends to become fuzzy.

When an image is uploaded at 1024px or smaller, as it should be, no sharpening or resizing takes place.

[Leftseat86]

Compression on Uploaded Photos

:S note to self: upload in 1024 now [img]images/smiles/icon_biggrin.gif[/img]

-Clovis

1024 only [img]nod.gif[/img]

[cicadajet]

Compression on Uploaded Photos

Chris, Whats odd is that of several images I uploaded recently, (ones that were a bit too aggressively sharpened on my end), they appear greatly degraded on JP from what they were when uploaded.. Mind you they were at 1024... But this is only when viewing through AOL. Checking on the same monitor, but not using AOL, they appear just as the original file did. Likely a problem with my own set-up, but thought I'd throw it out there in case there was a legitimate issue. Again, the difference is apparent in just a few cases that I've checked.

Tom

[Chris Kilroy]

Compression on Uploaded Photos

Tom,

AOL's browser uses built-in image compression, which can severely degrade the quality of all images being viewed with the browser. IIRC, there is a way to turn that off.

[PolishAir42]

Compression on Uploaded Photos

Or use Internet Explorer. Of course the best browser. [img]images/smiles/icon_biggrin.gif[/img]

[Anonymous]

Compression on Uploaded Photos

Hi all

My first image uploads, I have noticed some compression also, especially around titles and registrations.

Not sure what that can be.

Cheers

Gary Watt

[bfpires]

Compression on Uploaded Photos

I don’t want to say anything stupid, but I really thought you guys at jetphotos were applying some kind of compression on any and every uploaded photo.
I mean, just in order to keep pictures lighter for everybody to see...
What about the dpi size?

[LX-A343]

Compression on Uploaded Photos

Something happens to the pictures. I thought so far, it was the JPG compression. All I know is, that the filesizes of the Jetphotos pics are smaller, than the original filesizes (some 20% less in an average).

Gerardo

[lockon]

Compression on Uploaded Photos

I thought the same thing when I uploaded stuff this weekend. I noticed excessive JPG compression around the red objects in the photos. The red bleeds into the other areas a little.

I’m looking at the code that Chris posted now…

[ January 28, 2003 03:31 PM: Message edited 1 time, lastly by Sunil ]

[Anonymous]

Compression on Uploaded Photos

Hi all

Pics I uploaded yesterday with no pre-compression have uploaded to the site with no problems.

Seems like I have to upload the processed image 'as is' without compression via JPEG Wizard or similar.

Cheers

Gary