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Still not understanding how to avoid Compression rejections

Posted: Sun Nov 11, 2018 11:10 pm
by canyonblue17
Ok - I have more than 1,000 photos published here - yet I still get a ton of
Compression rejections. I’ve posted this problem before - and followed the advice - including reducing the original photo in steps rather than all at once. Meanwhile I shrink every photo exactly the same way and I will get a string of photos approved followed by a bunch rejected - from the same shoot. I always save at highest quality. I’m saving at only 1100 or 1200pixels wide. Apparently I still need plenty of advice - so bring it on. Thanks in advance as always.

Re: Still not understanding how to avoid Compression rejections

Posted: Sun Nov 11, 2018 11:56 pm
by fsx98
I've been there at one point or another while uploading photos to a.net; I may be wrong, but it's probably as a result of screener inconsistency, as these photos may actually have grain or noise in them, overlooked by screeners. In all cases, I have my photos saved in highest quality (minimal to no compression).

Re: Still not understanding how to avoid Compression rejections

Posted: Mon Nov 12, 2018 2:09 am
by Runway28L
An issue that sometimes causes a "compression" effect is when too much noise reduction is added to the background (i.e. the sky) in an image.

That's the only type of compression I've faced other than importing images improperly, although it's pretty rare since I usually do my best to not add too much NR.

Re: Still not understanding how to avoid Compression rejections

Posted: Mon Nov 12, 2018 10:50 am
by airkas1
Hi Mark,

That was me screening your photos yesterday. Unfortunately I'm not exactly sure what causes this (or how to solve it for that matter), but we call it 'blotchy sky'. There isn't really a proper rejection reason for it, so I usually give it noise/quality or compression/quality with a personal message.

For reference purposes (hope you don't mind, otherwise I'll remove them) I linked 2 of the photos, so the others can see what I mean.
1) top sky - https://imgproc.airliners.net/photos/ai ... bc63d12b7d
2) top left corner - https://imgproc.airliners.net/photos/ai ... 43aa6c04cc

Re: Still not understanding how to avoid Compression rejections

Posted: Mon Nov 12, 2018 11:43 am
by canyonblue17
No I don't mind you posting them at all. Maybe I can get more advice from those that see them. The thing that is the most frustrating is how I will get a bunch approved and then a bunch rejected from the same shoot, under the same conditions, that I edit almost exactly the same way. And I clearly am too blind to look at the screen and understand when I should/shouldn't use noise reduction correctly. I think maybe to play things safe I use it too much. Can that make a good photo turn bad?? Thanks again for all your help.

Re: Still not understanding how to avoid Compression rejections

Posted: Thu Nov 22, 2018 12:43 am
by cmandel
Hello everyone, I got some Compression rejections too, and it was because I overly slided the "blue" part of the Hue/Saturation/Luminosity tool. This caused the appearance of artifacts in the sky (JPG compression like).
Take a look if you are doing something similar with the HSL tool. Hope that it helps.

Regards