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Question

LR BUG? More noise in LR than in Photoshop when loading JPG

Forum|Forum|7 years ago
November 12, 2018
8 replies
2594 views

Hi all!

When loading JPEG in lightroom, I can see noise shaped like short horizontal segments of lines.

This does not appear in other images viewer such photoshop or GIMP. Is it a Lightroom BUG ?

how to avoid this bad looking noise ?

Here is the comparison, I increased the contrast so you can see it easily:

Left: Lightroom (Classic CC Version 1.4, Camera Raw 10.4), top right: photoshop.

GIMP behave like photoshop.

Here is the original picture:

Thanks for your help.

This topic has been closed for replies.

J

Jao vdL

Community Expert

Thanks ssprengel that confirms it is a general thing and not Mac only or dependent on GPU or some strange thing like that.

J

Jao vdL

Community Expert

Thanks ssprengel. You can actually see the artifacts in Lightroom without doing any edits. No artifacts in Photoshop. I only did a tone curve here. No sharpening needed. I can't get these lines in any other editor so it is LR/ACR specific.

J

Jao vdL

Community Expert

Here are screenshots. This is Lightroom with ONLY a curves adjustment:

Here is Photoshop with basically identical curves:

No line artifacts in PS.

The artifacts are visible in exports from Lightroom but not in Photoshop. You do get the same artifacts in camera raw if you dial in the same curves:

This might be that the math in Photoshop in only 8-bits precision is not capable of showing the artifacts that are there in the original file, so I tried opening the jpeg directly in Photoshop, converting to 16-bits and doing the same curves but you still don't see the artifacts in that case. Something is different in how Lightroom and ACR read these jpeg files from Photoshop.

GoldingD

Legend

Did you edit the image in Photoshop, create some layers in Photoshop, then save with the layers? Then back to Lightroom?

ssprengel

Inspiring

It doesn't matter what was done to create the JPG.

The point is that the same JPG is being used as input to LR/ACR-plug-in vs ACR-filter with the same settings applied and it looks different between the two.

J

Jao vdL

Community Expert

ssprengel wrote
It doesn't matter what was done to create the JPG.
The point is that the same JPG is being used as input to LR/ACR-plug-in vs ACR-filter with the same settings applied and it looks different between the two.

The only difference between the two methods is what code read the jpeg. If you use ACR as filter, the image data was already loaded into a Photoshop buffer and that data gets run through the ACR code. If you open the jpeg directly in ACR or Lightroom, it uses it's own jpeg decompression code instead of Photoshop. That is perhaps where the problem occurs.

J

Jao vdL

Community Expert

The interface in your screenshot looks incredibly strange. Extremely high contrast also in the interface elements like the menu bar and the buttons. Do you have a mode turned on such as increased display contrast? This is done in the system preferences on your mac in Accessibility->Display. You should not have anything enabled and the display contrast should be set to normal. It looks as if you have it dialed up. This will mess with the image display in Lightroom otherwise.

J

Jao vdL

Community Expert

Sorry you wrote that you increased the contrast on the screenshot. I checked your file and you are right if you dial in an extreme tone curve on it it will show stripes. Doing the same thing in Photoshop does not show the stripyness. This looks like a weird bug to me. Nothing to do with the GPU. No clue what causes it. Please report at https://feedback.photoshop.com

Todd Shaner

Legend

https://forums.adobe.com/people/Jao+vdL wrote
I checked your file and you are right if you dial in an extreme tone curve on it it will show stripes.

Jao I'm not seeing that on my Windows 7 system.

I also need to add sharpening and a high Dehaze setting to reveal any pattern artfacts, which look like sensor noise and JPEG compression artifacts.

Todd Shaner

Legend

matthieug84604588 wrote
Here is the comparison, I increased the contrast so you can see it easily:

The JPEG you uploaded has very low contrast, exposure, and sharpness. This requires increasing the exposure, contrast, and sharpening inside LR, which reveals sensor noise and JPEG compression artifacts. You can work around this issue by using LR's Basic and Detail panel controls as shown below.

A better solution is to adjust the camera's settings to obtain an image file with normal exposure, contrast, and sharpness.