JPG Artifacts

I have a few hundred photographs of Yellowstone, all shot as max res JPGs.

As I start to work with them, I'm seeing JPG artifacts pop up.

Is there a way to (a) eliminate them or (b) reduce their impact when working with these existing files?

I've never seen JPG artifacts when I load high res images. Are you working on them as JPG, saving them, then opening them again? if you do then you need to save as psd or tiff files until you save as JPG as the last step of your workflow. Also save as Q12 JPGs.

I did an experiment a year or so ago when I loaded a jpg, then saved it, did it ten times, it took ages for JPG artifacts to show up. Thread here. Post a 100% crop to show what you mean if you like.

removed

tim wrote in post #3173553
I've never seen JPG artifacts when I load high res images. Are you working on them as JPG, saving them, then opening them again? if you do then you need to save as psd or tiff files until you save as JPG as the last step of your workflow. Also save as Q12 JPGs.

I did an experiment a year or so ago when I loaded a jpg, then saved it, did it ten times, it took ages for JPG artifacts to show up. Thread here. Post a 100% crop to show what you mean if you like.

I actually think that I saw that thread a while back; interesting finding which I completely forgot about -- History on the files isn't clear, because we had no clue what we were doing, so I think these are hit with something from Elements 4 in batch on the Mac which just might have thrashed them; I'll go dig up the out-of-camera stuff ASAP!

I'll post a 100% crop after I'm done with PP from tonights sports shoot...... Could be I'm pixel-peeping too much (oh yeah, I do that)

Graystar wrote in post #3173982
I don’t know what you’re seeing, but they’re not JPEG artifacts. You would never see JPEG artifacts as you're working with an image.

JPEG artifacts manifest themselves after you’ve saved the file, closed it, and reload it from disk. If you’ve got JPEG artifacts then *that* is the time you’ll see them.

JPEG artifacts are 8x8 blocks that occur from too much compression. Take a look at this page for pictures of JPEG artifacts.

http://www.scantips.co​m/basics9jb.html

Yep, you guys are both spot-on; quick look reveals I'm not seeing this at all, which begs the question what am I seeing -- I'll have to post a pic and explain.

[Bang] shot by mod

hortonsl62 wrote in post #3174664
[Bang] shot by mod

Huh?

^^ For posting something totally incorrect; what I'm seeing is not a JPG artifact, so I'm wasting everyone's time.

Nah, people don't get told off for being wrong, otherwise i'd be long gone

Lets see what your seeing.

...1/2 way through tonight's shoot; hangin' it up for now.

I'll post a 100% crop tomorrow night.

Thx for any help you might provide, in advance.

hortonsl62 wrote in post #3175080
^^ For posting something totally incorrect; what I'm seeing is not a JPG artifact, so I'm wasting everyone's time.

My money is on Posterization.

Try making the same processing steps in 16 bit mode and see if it is any different.

Either that or over-sharpening.

Rad

(Hmmm... Maybe we should start a pool - $10.00 per square too much?)

It's always fun trying to guess what's wrong with a photo when (a) we haven't seen it; (b) the person who took the photo hasn't described the problem; and (c) we have no idea whatsoever what has been done to the photo in PP.

Converting your shots to 256 colour gifs will do that to ya....

Maybe you're looking at a magnification other than 25-50-100%?

Oooo I'm in big trouble now -- I went to snag the image for posting, looked harder -- that old JPG was shot in "landscape mode" on the 30D, ISO 320, so now I think it is just ISO noise leftover.

I love the photo; been playing with Shay's ATN and others for pushing the color around.

This one will be the first I use masks on to PP the sky differently from the mountains. Here's where it stands today, and it isn't nearly done. PP so far is a light application of Noiseware/Pro, USM x 2 85/1/4, 20/50/0 + the Shay's Rich Color Landscape, 60% opacity for that layer, otherwise I did nothing to saturation/colors.