Photoshop CS changing my Exif Data

In article ,
wrote:

I had a grayscale JPG with the "Image description" Exif field set to a description, and the ITPC "caption" field set to a different string. I made a change to the JPG file and close-with-saved the file. The resulting file got the ITPC caption copied over into the Exif "Image Description" field.

Upon further investigation I discovered that editing the ITPC Caption tag edits the Image description tag in Exif. What’s going in here? According the CS Manual, IPTC is the only modifable type of metadata. And it appears like I’m not going to be able to change my EXIF image description back without changing the ITPC to match.

Is this the intended behavior or a bug?

These two fields are aliases to one another. After consultation with customers who depend on various metadata schema aliasing in the interest of metadata appearing where users and other software expect it we aliased some fields to one another.

–marc

Hi Marc,

Thanks for the answer. Some questions: Is there someplace I can find out the exact list of what tags are aliased, which tags take presidence, and when they’re syncronized? It’s kind of important.

After consultation with customers who depend on various metadata schema

I’m a customer who depends on metadata. I sort and tag sometimes hundreds of images a day. I’m paid by other companies to apply and sort by EXIF data. Here’s my take on the situation.

What conserns me is that when Photoshop saves a file where the Exif and ITPC tags were different, and neither were blank, Photoshop overwrites the EXIF tag, basically throwing out that data with no warning. Since EXIF data is generally not-user-editable by applications, I find this suprising: Photoshop overwriting a valid non-editable tag with the contents of an editable one. If I wasn’t checking my data closely I would have missed it.

Here’s how I it should behave:

1. Don’t alias the EXIF data just on a save. If tag editing occurred, don’t take the contents of one field and overwrite another with it. The reason is no one would ever expect this to happen, and the only way to find out about it (apparently) is to stumble on it accidentally. This really, really messed me up. It blew away EXIF data on about 150 files of mine, and I didn’t realize what was going on for a few hours afterwards. My entire work for the day was shot while I retraced my steps to figure out what went wrong.

If the people you consulted with needed the data in the two fields aliased, then allow them to apply an action or click a button in the file browser or something to have them aliased. This alias should not be automatic.

2. If the value of the ITPC caption tag and the EXIF desciption tag is the same, or the EXIF field is empty, then editing the ITPC caption tag will change the EXIF description tag, too. Otherwise, don’t overwrite the EXIF with the ITPC.

Whatever photoshop does, it should NOT just write over a unique tag with it’s own data (esp. a tag that is not editable).

I’d be happy to talk with you in more detail in email if you’re interested in *my* metadata needs.

Thanks,

~Hanford

In article ,
wrote:

Thanks for the answer. Some questions: Is there someplace I can find out the exact list of what tags are aliased, which tags take presidence, and when they’re syncronized? It’s kind of important.

EXIF Software is aliased to AgentName
EXIF Artist is aliased to ProperName
EXIF DateTime is aliased to Date
EXIF ImageDescription is aliased to IPTC and XMP Caption EXIF Copyright aliased to IPTC and XMP Copyright

After consultation with customers who depend on various metadata schema

I’m a customer who depends on metadata. I sort and tag sometimes hundreds of images a day. I’m paid by other companies to apply and sort by EXIF data. Here’s my take on the situation.

What concerns me is that when Photoshop saves a file where the Exif and ITPC tags were different, and neither were blank, Photoshop overwrites the EXIF tag, basically throwing out that data with no warning. Since EXIF data is generally not-user-editable by applications, I find this suprising: Photoshop overwriting a valid non-editable tag with the contents of an editable one. If I wasn’t checking my data closely I would have missed it.

The specification for EXIF and IPTC have also led other users to expect the two would and should be aliased. This required a policy decision. You raise a valid point about EXIF fields that are generally considered immutable. Some EXIF fields, such as "time of last modification", though, are expected to be modified to correctly reflect the time of last writing.

Here’s how I it should behave:

1. Don’t alias the EXIF data just on a save. If tag editing occurred, don’t take the contents of one field and overwrite another with it. The reason is no one would ever expect this to happen, and the only way to find out about it (apparently) is to stumble on it accidentally. This really, really messed me up. It blew away EXIF data on about 150 files of mine, and I didn’t realize what was going on for a few hours afterwards. My entire work for the day was shot while I retraced my steps to figure out what went wrong.

We have some users that expect updating one field will propogate to aliases of the field, even if those aliased fields are not empty and contain different data in other schema and would view your suggested behavior as a bug.

If the people you consulted with needed the data in the two fields aliased, then allow them to apply an action or click a button in the file browser or something to have them aliased. This alias should not be automatic.

2. If the value of the ITPC caption tag and the EXIF desciption tag is the same, or the EXIF field is empty, then editing the ITPC caption tag will change the EXIF description tag, too. Otherwise, don’t overwrite the EXIF with the ITPC.

Whatever photoshop does, it should NOT just write over a unique tag with it’s own data (esp. a tag that is not editable).

What about the EXIF ImageDescription tag should make it not editable?

I’d be happy to talk with you in more detail in email if you’re interested in *my* metadata needs.

We are always interested in hearing when Photoshop does something unexpected. In this case it is a policy decision and one we can discuss here as to whether the decision should be revisited.

–marc

Hi Marc,

Thanks for the answers.

Marc wrote:

We have some users that expect updating one field will propogate to aliases of the field,

Two points on this comment:

1. It’s not just when you assign a new IPTC flag, it’s when you save the document. If this alone were changed so it only aliases when you *change* an IPTC tag, it would be a major improvement.

2. I don’t know why anyone would expect it to work the way it does, unless they have been clued-in to that behavior in Photoshop (either by stumbling onto it, or by being a beta-tester and requesting it specifically). In both cases its a learned expectation. I think *any* other user other than that would NEVER expect it to behave this way. It’s not a natural assumption, and I could not find reference to it in the docs.

and would view your suggested behavior as a bug.

Right, these people, who somehow expect it to work this way, would think it’s a bug. Just like I think it’s a bug now. But the current behavior overwrites valid, unique data in a field in a very "hardened" field that does not change in virtually any other editing application, without telling the user, and without recovery, and without choice. Just by saving the file it’s commited. That sounds like a bug to me.

Becuase ITPC takes presidence over EXIF, It basically renders any workflow that depends on EXIF tags useless, if I’m going to be editing in Photoshop, since I can’t expect any of the data to be the same once I save (even if I made no changes to any tags). So now I’m going to need to come up with a way to cache the EXIF data before editing and then reapply it to the file after I’ve saved! Come on!

What about the EXIF ImageDescription tag should make it not editable?

The de-facto standard is that it’s not editable. Most of the software out there that deals with EXIF deals with it in a read-only fashion. Photoshop itself does not let me edit it directly (it tells me it is not modifable). For all intents and purposes, it’s not editable. To get a tool that modifies it you need to get some custom specialty software — there’s not a lot out there. So chances are the data in the EXIF field was assigned there in a very specific manner — either programmatically in a way that is hard for a user to change back, or very deliberately becuase the data there is NEEDED. And so when I make a change to an EXIF field, I don’t expect other tools to blow those changes away. I don’t think anyone would expect that.

In short: I understand it’s a policy decision. But I don’t understand why the decision was made to aid some user’s workflows (how many?) at the expense of crippling any workflow that depends on EXIF data rather than IPTC. To have to cache the EXIF data before editing and reapply afterwards will be impossible for most users. I think a policy decision that allows one to work with EXIF or ITPC would be a much better choice.

In any occasion, don’t blow away data without notifying the user.

~Hanford

I’m never one to just post a message with the vacuuous "atta boy!", or "I agree.", but it’s hard to avoid it this time. Regretfully, I have another reason to add to the argument: I just had the same problem, but was totally unaware that PS was blowing away this exif data on images I’d been dealing with for years, not just a few hours. It wasn’t till I finally got a good exif-viewing package that I could incorporate into my own website where people could view exif data on my pictures that I discovered massive loss (on a quantity scale; not so much a "quality" scale. 🙂

I also like to pride myself on considering both sides of an issue, and the only one I can see from the PS side is that they had users request it, and if it changed, they’d view it as a bug. Yet, given the counter-arguments, I’d say it’s a problem that will only get worse if not addressed soon. Sometimes it’s better to just confess "mea culpa" and fix it, warning those few existing users that depend on this that it won’t be supported anymore (and provide reasonable workarounds and appropriate UI dialogs, etc).

Of course, this assumes that the "issue" will be addressed in some next/future version. I sure hope it will be; for the moment, I only request having a "sense" of what the decision-makers are thinking at this point, as I’ll want to prepare for that time with programming now.

In article
wrote:

I’m never one to just post a message with the vacuuous "atta boy!", or "I agree.", but it’s hard to avoid it this time. Regretfully, I have another reason to add to the argument: I just had the same problem, but was totally unaware that PS was blowing away this exif data on images I’d been dealing with for years, not just a few hours. It wasn’t till I finally got a good exif-viewing package that I could incorporate into my own website where people could view exif data on my pictures that I discovered massive loss (on a quantity scale; not so much a "quality" scale. 🙂

What specific tag changes in the various metadata schema were unexpected for you, Dan?

–marc

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