P: Save Metadata To File sometimes writes huge .acr sidecars for JPEGs unnecessarily

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​@drtonyb If I Save Metadata to File [on the raw], I get this error: … I also tried Importing your test photo into one of my own test catalogs

I tried the recipe with a fresh downloaded copy of the .zip on a different Windows 11 machine (real, not virtual) and it went as expected.  So I’ve tried it on a Macbook, Windows 11 Intel-on-Mac ARM virtual machine, and Windows 11 Intel.

My only thought is that there’s an incompatibility between the Mac default compression of .zips and the utility getting invoked on your Windows for uncompressing .zips.  I’ve got the Windows 11 default uncompression.

​@johnrellis 

This is what I see when I open your test catalog:

If I Save Metadata to File, I get this error:

If I remove your test photo, then try to Import it again, the Import dialog cannot display a preview and this is what I get when I do try to Import it:

I also tried Importing your test photo into one of my own test catalogs and got the same result.

It’s all very weird because your test catalog doesn’t have any Previews, so LrC must be reading the RAW file and generating a preview when I open your test catalog as provided.

My testing also shows that an Export as a TIFF doesn’t get any Sidecar Files, nor does it get a .acr file when Save Metadata to File is executed.

​@johnrellis 

I’m having a problem with your test catalog and the whole premise of this bug.

I can open your catalog on my Windows PC and see your test photo in LrC. I note that the Sidecar Files is xmp, acr, but your test catalog doesn’t contain the .acr file.

I removed your test photo and tried to Import it. LrC can’t generate a preview in Import and if I Import it, LrC reports that it cannot read the file because it is corrupted.

So, I did your test with my own file. Applied Denoise to a photo, Saved Metadata to File for the RAW so that it created .xmp and .acr files. After Exporting to a JPEG with Include: All Metadata, I note that the JPEG has Sidecar Files acr when Imported. I think this is wrong. A JPEG can’t use .acr data for Denoise; LrC can’t denoise JPEG files.

I start over after removing my test photo and Importing it again. I Denoise, but don’t Save Metadata to File. Export to JPEG and Import; the Sidecar Files field is blank as expected.

I start over again. Save Metadata to File for my RAW, close LrC, delete the .acr file and relaunch. Export to JPEG and Import it. The Sidecar Files field is blank. Save Metadata to File for the JPEG; the Sidecar Files field is now acr. Again, this is wrong, but worse is what you observe, a .acr file is created and attached to the JPEG. So the .acr file is associated with the RAW file and the JPEG file. Deleting the JPEG fro the drive with LrC deletes the .acr file too. That’s also bad.

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A workaround is to export non-raws with the setting Metadata > Include: All Except Camera Raw Info.  This ensures that develop settings are not included in the exported files.

Note that the option Catalog Settings > Metadata > Include Develop Settings In Metadata Inside JPEG, TFF, PNG, and PSD files doesn’t affect the bug. This setting controls the behavior of Save Metadata To File and Automatically Write Changes Into Sidecar Files for files that are cataloged, not files that are exported.

Moderators, ​@Sameer K, please merge with this bug:

A bug causes Save Metadata To File (and Automatically Write Changes Into Sidecar Files) to write .acr sidecars for a non-raw that was exported/re-imported from a raw to which an AI command has been applied (AI masking, Denoise, Super Resolution, AI Remove). 

In your situation, removing a color label from the exported/re-imported JPEG changes the Metadata Status to Has Been Changed. Automatically Write Changes then writes the changed metadata to disk, and the bug causes the .acr sidecar to also be written;

This sounds like the same bug I reported, where removing a label on a JPEG or PSD will create an acr file. My report got ignored. :(

I wrote a Photoshop script to remove the label (since that ability is not available in the GUI) so I can bypass the whole problem and just deal with it before I save a file. I still think this is a bug but hopefully this is a viable workaround.

try{
    if(ExternalObject.AdobeXMPScript == undefined) ExternalObject.AdobeXMPScript = new ExternalObject('lib:AdobeXMPScript');
    var docRef = app.activeDocument;
    var xmp = new XMPMeta(docRef.xmpMetadata.rawData);
    if(xmp.doesPropertyExist(XMPConst.NS_XMP,'Label')){
        xmp.deleteProperty(XMPConst.NS_XMP,'Label');
        docRef.xmpMetadata.rawData = xmp.serialize();
        }
    }
catch(e){
    Window.alert(e + e.line);
    }

Ok, I’ll rephrase. How do I limit writing XMP/ACR sidecars to RAW files (which I want) and not to JPEG and PSD files (which I don’t want)?