Best practices for photo metadata?

October 30, 2009 7:14 AM

Best practices for recording photo metadata? What I'd like to be able to do inside, plus many questions about what's possible today or likely to be possible in the future.

Let's start with my ideal vision: I'd like to be able to record various metadata within image files, and have them automatically and correctly transferred to photo-sharing websites, apps, etc., that I might upload/import said images to. The basic idea is that I'd like to associate the metadata with each photo once, so if I upload them to Flickr today, and to Smugmug in six months, and a website or app which doesn't exist today two years from now, I only have to enter all the metadata once and don't have to re-enter it for each new website/app I'm using.

The particular information I'd like to be able to record includes:
*Time/Date, ideally including time zone, although the EXIF specification doesn't record time zone
*Location, from GPS data (lat./long./alt.)
*Title
*Caption (or call these two "short caption" and "long caption" or whatever you want; the point is that in some places a description of a few words is appropriate, for some several sentences may be; I'd like to be able to record both)
*Keywords, a.k.a. tags (but subject tags, a la Flickr, not to be confused with the metadata fields in general which are also sometimes called tags)
*Copyright statement
*License statement (e.g., a Creative Commons license)

I've seen this website and these guidelines. From the latter I gather there's three standards in at least moderate use, EXIF, IPTC-IIM, and XMP. I know websites such as Flickr and Smugmug currently read EXIF data and make use of some of the fields; are there any that read IPTC-IIM or XMP? Is this likely in the future? Is it worth even bothering to try to record metadata in IPTC-IIM or XMP? If so, any suggestions for tools to use (under Windows XP and/or Vista)? I have an EXIF editor, so I don't need recommendations for one of those, but if there are tools which allow one to edit EXIF plus one or both of the others, I'd be interested

Date/time and GPS data are already pretty well in place. Date/time is recorded in EXIF by the camera when I take the picture (except for not encoding a time zone), and I've managed to figure out how to geotag them in bulk in the EXIF data if I have a GPS log. And date/time and lat./long. are already used by Flickr and Smugmug. What about other fields (where the fields even exist)? Are titles, captions, license, etc., appropriately made use of, or do they just sit there, visible in the EXIF data but not applied further? What's the status in other websites or apps? Any ideas about what it's likely to be in the near future?

If there currently isn't a good/useful way to record some of this metadata in the image file itself, any recommendations for recording it elsewhere (in a separate file or files) so it would be relatively easy to add it to the image files if it became possible/useful in the future?

If it makes a difference, I only need to do this for JPG files. That's how they come off my point-and-shoot, so I don't have RAW files.

Any comments on the "big-picture" (heh) issues I've implicitly brought up here, or recommended reading on the topic, are welcome too even if I didn't specifically ask about them.

posted by DevilsAdvocate to Computers & Internet (7 answers total)

I use Apple's Aperture and any additional metadata that I throw in is stored as IPTC. I can tag images (with or without a heirarchy) like flower, rose, red and I can do the same with people, family, Uncle Bob, etc. When exporting images, it will embed this metadata in the image or I can exmport an XMP sidecar. Aperture lets me quickly search, for example, for all photos rated 3 stars or better with the tag flower or any flower sub-tag. It also makes bulk metadata fairly easy to handle, though I can always use the ever handy exiftool to write metadata directly if I so choose.

You're not a Mac user, so I guess LightRoom is what you'd use and I'm pretty sure you can find a pre-compiled exiftool binary in case you needed it.
posted by Brian Puccio at 7:36 AM on October 30, 2009

There are caption and copyright fields in the EXIF that you can insert for sure. Location is supported in EXIF and it looks like you have that sorted. Looks like there's a License tag too.

There's an XPKeywords tag which I think you can use to store content-tags a la flickr in each jpeg for safekeeping, but that approach is not easily searchable.

In terms of tags, the usual approach is to use a separate application and store the image/tag relationships in a relational database, which means you can search for images by tag without having to read a bazillion jpegs to determine which ones have the combination of tags you want. There are many such applications (what OS are you on? people can probably make recommendations and I'm about to publish an open source project that does this) but I think the main issue is the longevity and portability of your tags. I wouldn't want to put them into some closed app and then have to redo or face losing my tags; if it's possible to insert them into the file via XPKeywords or similar then that's probably a good backup plan because it would allow the automated reconstruction of a tag database from the jpegs.

Get exiftool and have a play with it. The -list option will give you a massive list of supported tags.
posted by polyglot at 7:49 AM on October 30, 2009

Sorry, looks like there's Keywords, AppleKeywords and XPKeywords and a couple others. Using the Keywords field might be better.

Using exiftool I've mangled a jpeg I have here to contain a bunch of your requested fields. Here's the output, with irrelevant lines elided:

vetinari:~%exiftool wave_th.jpg
ExifTool Version Number : 7.67
File Modification Date/Time : 2009:10:30 22:55:41+08:00
File Type : JPEG
MIME Type : image/jpeg
JFIF Version : 1.01
Exif Byte Order : Big-endian (Motorola, MM)
Copyright : 2006 William Brodie-Tyrrell
Keywords : a list of keywords
XMP Toolkit : Image::ExifTool 7.67
License : restricted use
Title : Charlie Waving
Comment : This is a very long caption
Image Width : 294
Image Height : 384

All that was done using 'exiftool -Fieldname="Values" filename.jpg' commands.
posted by polyglot at 7:58 AM on October 30, 2009

Response by poster: what OS are you on?

Windows. One computer is on XP and one is on Vista.
posted by DevilsAdvocate at 8:30 AM on October 30, 2009

I believe a lot of people use Lightroom for this purpose on Windows.
posted by polyglot at 4:03 AM on October 31, 2009

[url=http://www.dyxum.com/dforum/forum_posts.asp?TID=54046]This thread[/url] may also be of some assistance.
posted by polyglot at 8:09 PM on October 31, 2009

dammit, This thread. Teach me to spend too much time on phpbb boards.
posted by polyglot at 8:12 PM on October 31, 2009