P: Select Sky causes export to be larger than expected

[andrewl21008093]

I've been asked to report this as a bug in Lightroom Classic v11

When a Select Sky mask is added, and 'All Metadata' is selected for export, an error message is generated, screenshot attached. This forces the user to choose a larger file size that may be desired in the circumstances. If a different Metadata setting is chosen, the problem does not occur.

It seems that Select Sky and All Metadata have a compatability issue.

[giovannil15990362]

hier the exported jpg.

and hier the link for the raw and xmp

https://www.dropbox.com/sh/b2xza80sf456xgj/AABgKG9MVR6CTseOwC1pvR2ka?dl=0

[Jao vdL]

This image is much too complex to not get artefacts at 550kB size and 2500 pixels in jpeg. You will need at least 1 or 2 MB for this to not artefact in jpeg. I don't think this has anything to do with the AI mask but probably what happens is that applying the mask just makes the jpeg algorithm focus on different things in the image forced by the low quality setting it will have to use for the very restricted filesize. Remember that what happens at export is that Lightroom renders the image at full quality and full size first and the scales down to the final size. Only then does it apply the jpeg compression. The masking in your image can only have an impact on the final image after compression because it affects the actual image content. Jpeg compression is a perceptual and lossy compression. It tries to spend its attention on the most visually impactful detail and throws away info from parts it thinks matters less. This is why at low quality settings (which is where you force it by the very low filesize for the image size setting) you typically start seeing posterization artefacts in parts of images that are smooth gradients. So this is quite expected looking at your export settings and likely only happening because your mask makes areas of the images more prominent and carry more weight in the jpeg compression step.

note I am only looking at the images on my phone. Can take a look on my desktop later

[giovannil15990362]

thank you Jao,

have a look on your pc as well. all your reflection may be correct. Altough I can't explain why you see a difference in between the "with mask" and "without mask" they are the same export only change is the presence of the subject mask. the one without render out as it should be.

[Jao vdL]

I downloaded the arw file from dropbox and imported into Classic. I don't see any AI mask in it though. It is not embedded in the xmp. What kind of mask were you applying?

[giovannil15990362]

sorry about that.

I re upload the updated .xmp

and I attache here as well

[Jao vdL]

Hmm, I just added a "select subject" AI mask (it selects the dresses in the foreground and one of the hats on the rack at the right) that is set to not do anything (all sliders at zero) and after that Lightroom will refuse to export at the settings you quote above saying that the selected filesize is too small to be able to export to. It export just fine (and without artefacts indeed) without the AI mask. This shouldn't happen as the AI mask is set to not do anything so the image should be identical. This might indicate a bug somewhere indeed. Not sure why your machine actually does do the export and mine just throws up the error message. 

Sorry for not answering in German. I can read it just fine but writing in German is a whole other problem 😉

[giovannil15990362]

English is fine. I am italian. I wrote in germane becuase I tought I was in the german comunity but i realized that I was in the international one. which is great. I select of course the person. in my xmp should be the person seleted and a subtraction brush for the coats.

yes somethimes  i do get the same export warning that I have to increase the file size. This happens to especially when I have masks or I have recovered too much in schadows and highlights.

best,

gio

[Jao vdL]

Ah. Just downloaded your xmp. The AI mask is just selecting the person at the rear and you have dialed in some brightening to make him pop a bit. When I export with your settings, I get a heavily artefacted jpeg with lots of posterization in the walls. The one without the mask active is completeley clean. This really should not happen as the only slight change is the brightness of the person and that really should not affect the rest of the image as much as it does. I think you are right that this is a bug. The presence of the mask should not affect the export process this much and I am not sure why it does here. As I understand the rendering chain in Lightroom, there should be basically effect or only the small subtle effects I described above.

[John R Ellis]

This is an instance of an existing bug that Adobe has acknowledged (with Jao's help :->):

https://community.adobe.com/t5/lightroom-classic-bugs/p-select-sky-causes-export-to-be-larger-than-e... 

What appears to be happening is that the presence of the mask is causing LR to incorrectly overestimate the final exported file size, so it lowers the chosen JPEG quality too much, causing banding artifacts in the ceiling. There are two workarounds:

1. Set the option Metadata > Include: All Except Camera Raw Info instead of All.

2. Instead of Limit File Size To: 550 KB, use Quality = 61.

The table below shows the results of Quality: 61, Limit File Size To: 550 KB and Include: All, and Limit File Size To: 550 KB and Include: All Except Camera Raw:

I've attached the output files.

[John R Ellis]

Moderators, @Rikk Flohr: Photography, please merge with the acknowledged bug report:

https://community.adobe.com/t5/lightroom-classic-bugs/p-select-sky-causes-export-to-be-larger-than-e...

[Jao vdL]

Yes indeed. Known bug it turns out. I wish my memory was better 😉 

[giovannil15990362]

Thank you john and Jao, I did miss that bug report!

lets hopfully wait for a fast bug fix from adobe.

[GoldingD]

So the Integrated Video Control drive version or perhaps bug with rigs with only an integrated video control, hence rolled into the large discussion. This group of users has a few things in common

• Integrated video controller, no desecrate GPU
• Integrated Video controller driver out of date
• They rely on in computer software provided by laptop manufacturer to keep drivers up to date
• They refuse to go to chip provider (Intel) for driver updates
• They think going outside the laptop manufacturer for driver updates will damage the computer or void the warranty.
• The issue is on a broad range of Intel integrated video control.
  • Of those members that have stated the brand of computer or motherboard, three or four stated ACER,two stated ASUS. One ACER owner listed ACER model, looking at ACER website, the available drivers were from 2016. Apparently ACER is not keeping regular updates for old models.  Both members with ASUS found the installed driver update utility from ASUS was out of date, upon updating, they were able to acquire new drivers, one fixed entirely, other mostly.
• Using Select Sky fouls things up.

Note that the Adobe Techs have acknowledged this as a possible Bug, and are investigating.

[giovannil15990362]

Hi,

thanks.
yes it could also be that. The plug-in to update my intel drivers clearly
recommends that I don't overwrite the customized microsoft drivers...as you
know with microsoft schit happens too often. But anyway I have the same
issue on my lenovo workstation with 4gb nvidia graphic card where davinci
studio 17 has no problem on running. I do really think it is a bug. I stop
using all metadata and render as should.

[John R Ellis]

I'm sure this isn't a driver-specific bug, since it can be reproduced on many different computers (e.g. on my Macbook Pro with a Radeon Pro Vega GPU).  

[Rikk Flohr: Photography]

This should have been fixed in the 11.1 update released earlier this week. Can anyone here confirm that you are no longer seeing the issue?

Thanks!

[JohanElzenga]

Looks like it's indeed fixed.

[Rikk Flohr: Photography]

Fixed in 11.1

[andrewl21008093]

Fixed for me too for several tested file sizes down to about 200k, which is fine - thanks!