I think you have a big, crawly, squiggly bug here.
It looks like a number of users have experienced similar issues.
The Photoshop document ancestors tag is written every time a file is "saved as", or has an element from a different file placed in it. Ancestors data is inherited from, well, ancestors. But still, it would be pretty tough for a human being to rack up tens of MB worth of that kind of log data.
There is an option in Photoshop to turn on writing yet more log data - logging every save of the file, or optionally logging every single action that is done in Photoshop. That can lead to giant blobs of metadata. But by "giant", I mean tens of KB, not megabytes.
I would think that it would take a malfunctioning machine to generate the kind of bloat we're talking about here.
UPDATE: The OP (to whom I am married, for the sake of full disclosure) provided me with the files in question and I examined them.
Two of the images placed in the final PDF had excessive Document Ancestor tags. One was the Tiff Bonnie mentioned in the original post, the other was a JPEG. The Tiff should have been about 25 MB, but was 56.5 MB. The JEPG was 19.8 MB when it should have been 1.7 MB. The stock photo image that was the base image for the bloated Tiff was free of corruption. It had very tidy metadata.
That suggests that Bonnie's copy of Photoshop, or another in her company may be the offender, making the corrupted files. That's not for certain, though, because the corruption may have been inherited from an ancestor to one of the bad files.
In the case of the Tiff, ExifTool displayed some 37 KB of Document Ancestor entries - over 1,000 entries. But when that tag was removed from the file's metadata, the files size dropped by 30 MB! Very curious. I suspected that the ancestors data might have been a symptom, rather than the problem, but given that blanking that single tag effected the reduction in file size, that seems doubtful.
I tried to find a clever GUI-based fix for these files without much success. The fact that the subject file was a Tiff and further that it was in CMYK eliminated most of the software I had at hand from consideration.
Opening and re-saving the file in various formats in Photoshop didn't work. (And ancestor data survives copy and pasting onto a blank document, that's the idea of it.) Nor did opening the file and exporting it from Lightroom.
I was able to use Photo Mechanic to strip all XMP metadata from the file. Oddly, there was no immediate impact on file size, but if I then opened the file in Photoshop and did a save-as, the file shrank to a normal size. IIM metadata was preserved, but of course, not XMP.
If I simply did "Save photo as" in Photo Mechanic, the corruption was removed, but the file was saved in RGB, which wasn't so good. Ditto for the JPEG. A simple "Save photo as" removed the bloat, but the resulting file was RGB. All useful metadata was preserved in this case.
XnView, ON1 RAW, and Apple Preview all failed to be of assistance.
The only program I had at hand that was effective was ExifTool. It's free and it doesn't take up much disk space, but it's command line, so it may not appeal to everybody. The advantage of using ExifTool to fix this issue is that you can remove just the offending tag and leave all the rest of the file's metadata intact. The ExifTool command you'll need is simply
exiftool -XMP-photoshop:DocumentAncestors= yourFile.tif
(Note that there are two spaces after the equals sign - one to tell ExifTool to blank the tag and one before the next argument)
I didn't try Stephen Marsh's Photoshop script.
There are programs floating around that indiscriminately strip metadata from images. I don't know if any will work on Tiffs or on CMYK images. I don't tend to recommend tools that do anything indiscriminately, so you're on your own if you want to go that way.
It's worth noting that removing metadata in bulk should be approached with caution. If a file has useful metadata (caption, copyright notice, etc.) that data should be preserved, especially if the file will be kept in your archive or published on the web or distributed. One of these images is from Getty Images. A Getty picture with stripped metadata is a dangerous thing to have lying around. This cautionary tale lays out about two billion reasons why (not a Getty image, but the same principle applies) : 2.1 Billion Rand copyright suit - CARL SEIBERT SOLUTIONS
As far as repairing the oversized PDF, a solution from one of Stephen Marsh's posts worked great for me. In Acrobat DC, going to "Optimize PDF > Advanced Optimization > Discard User Data > Discard document information and metadata" did the trick. The 55 MB PDF deflated to less than one MB.
I have in the past written about Photoshop logging data and how it can go terribly wrong. The horrifying story of Paul Hansen's ordeal, found in this post: Macron portrait meta-mess - CARL SEIBERT SOLUTIONS might be interesting.
So there's pretty clearly a bug in some versions/copies of Photoshop that should command some attention from Adobe. And, in my opinion, Adobe could reconsider whether or not to even have that Document Ancestors tag. I've never seen a workflow where it is useful. And it seems to cause all kinds of trouble, both socially and technically.
20
Replies
AdChoices