Researchers in the humanities often take a large number of pictures during their work: places, people, but also archival documents as a quick scanning replacement. This leads to very large picture collections that can be slightly overwhelming. Here are some tips from Guillaume Pasquier to help you sort through all these files using the embedded file metadata.
What is in an image’s metadata?
Metadata is data about data: information about the file that is included within it. When you take a picture, your camera will automatically generate some metadata, but you can complete it to make your files easier to use, share, and search for.
Technical metadata automatically embedded by your camera can include:
- Camera information (brand and model)
- Aperture, shutter speed, ISO number, focal depth
- Dots per inch (DPI)
- Date, time, and GPS location if available
Descriptive and administrative metadata can be included using most picture management software:
- Keywords, captions, comments, etc.
- Contact information
- Licensing rights
The last items are of course particularly helpful if you prepare your photographic collection for sharing as research data.
Which metadata format can you use?
Different image metadata formats coexist within most image file formats (JPEG, TIFF, PSD, Raw, etc.). The most widely used are:
- EXIF Exchangeable Image File
- IPTC Information Interchange Model
- DCMI Dublin Core Metadata Initiative
- PLUS Picture Licensing Universal System
- XMP Extensible Metadata Platform
The advantage of EXIF metadata is that it is searchable and writable directly from your Windows Explorer interface using right-click > Properties > Details.
No GIF or PNG
Please note that the PNG file format, while interesting for web publication (compression, transparency), does not accept EXIF metadata. Neither does GIF, but that is not a file format you should use beyond memes.
Using metadata in Adobe Bridge
Adobe Bridge is a free application from the Adobe Creative Suite which allows you to edit advanced metadata (EXIF & IPTC) for many file types.
You can also create “smart collections” that display only files that contain specific information in their metadata. This means that after enough metadata preparation, you could identify all pictures of red houses taken in Afghanistan between 01.03.2017 and 03.03.2017, or pictures of memos between Richard Nixon and Gerald Ford dated June 1972 from the hundreds of documents you scanned in the US National Archives. Searching your photographic archives then becomes much faster.
For more information on using Adobe Bridge metadata (and image metadata management in general), check out PhotoMetadata.org or this short video tutorial on renaming image files and applying metadata with Adobe Bridge.
Other applications allow you to apply metadata to files and manage them in batches, such as FastPhotoTagger, ExifTool, ExifPro, etc. We did not get to use them and therefore can not recommend any of them in particular. Comments are of course welcome if you have any experience with them.
Do you need help with research data management? Please contact Guillaume and the rest of the research data team at firstname.lastname@example.org
Original picture (cropped) : Alexandra, München (CC0 licence)