Other interesting tags include the “Make” and “Model” tags, which can tell you what type of camera or computer was used to create the media. One of the simplest tags is “Creation Date,” which naturally points to the time when its creator pushed the shutter button, or pressed record. But if you pry into any digital artifact, you can see metadata as a list of keys (or tags) and their corresponding values. Metadata exists in the parts of images, videos, or music that we can’t experience as humans. But in the wrong hands, this same information could be damaging. This information comes in handy sometimes, like when you’re flipping through old pictures by date, or by location. It describes the who, what, when, where, how, and sometimes even, why, for any document, video, photo, or sound clip. This piece has been cross-posted from Freedom of the Press Foundation. So every now and then we get a post wondering why they can't change the ModifyDate. An example of this is some Sony cameras (I think) write EXIF:ModifyDate to IFD1, instead of IFD0 which is where it is supposed to be located. If you try to be specific, you may write the tag to an incorrect location. The EXIF groups are named IFD0, IFD1, InteropIFD, ExifIFD, and several other names. Trying to be specific when your not familiar with the tags can lead to problems. By default exiftool will write tags to the more common location and will avoid the more obscure ones. For example, while xmp:xmp-photoshop:city will work, it's overly detailed. I should also say that it's usually best to keep the tag names simple in order to avoid possible problems. xmp-photoshop:City is the only tag that actually exists in your last paragraph. But you need to check the tag names page for what the actual tags are.
It all depends upon the options used as to what is displayed, but if you ask for xmp-photoshop:City, you will only get that tag, not any other tags with similar names. QuoteIt will only extract it as photoshop:city or xmp:xmp-photoshop:city and not inform the user that fields from different namespaces are part of a broader spec? So we will not see a duplicate entry xmp:xmp-iptccore:city come from ET? You only report/extract the base identity? So, xmp:xmp-iptccore:city is not valid? Is there any other means by which to associate fields from other namespaces? At least that's what seems to happen with GPS tags. I'm not sure but Composite tags may override as they are the last created. I believe that there's no guarantee as to which tag gets shown when there are duplicates, as I think it depends upon the order the tags are in the file. And you need to clarify what you want in cases there are duplicates from different groups. QuoteExifTool will not show this relationship, correct?Ĭorrect, exiftool will show only the information you ask for. Side note, I read somewhere that one of the reasons for Location structured tags is the fact that the original specs never made it clear whether the older tags where supposed to mean the location where the image was taken or the location where the image was shown.
Heh, I've probably made everything even more confusing. See Structured Information for more details on structured tags.
And then, since they are structured data, exiftool gives the option to write those as Flattened tags (rather than having to input the entire structure at once), using the names LocationCreatedCity and LocationShownCity. The City entry there only shows "Iptc4xmpExt:City", but obviously more info is needed as to whether it is Location Created or Shown. And that becomes another example of not confusing Schema vs Tags. Not all of the IPTC Core schema tags are part of the XMP-iptcCore group.Īlso, to complicate things, the XMP-photoshop:City is a "Legacy" tag in that it is being replaced by the Location created and Location Shown in the Image structured tags, which both use the Location Structure as sub-tags. Also, you have to make sure not to confuse IPTC Core schema as shown in your link with the XMP-iptcCore tags. You have to be careful not to assume that what other sites or programs call a field that it will be the same in Exiftool. "photoshop:city" is what the IPTC spec calls it. IPTC has declared that photoshop:city is a valid legacy field that is part of the IPTC Core. OK, I think I am getting closer to understanding.
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