So what is the big deal about photo metadata?
Recently I participated in three onsite seminars in Seattle, SF and LA as part of an SAA tour to educate photographers using a grant from the Library of Congress Digital Preservation project.
Simply put photo metadata is data about an image. Basic metadata tells who made it, what is the subject, when, where and how it was taken etc. etc.
None of this data is part of the visible image itself. It can only be stored hidden inside the image file. It has to be deliberately added; and it can easily be removed. Much of the SAA presentation covered the value for photographers and the various tools available. Details are being psoted to the Photometadata website
Since search engines are completely text-based, they can only recognize and find text strings. It can be very difficult to find specific images on the web or to find out more about a specific images. Metadata can help with search only if it is also on the page where the image is displayed.
In terms of identifying photos, the jpeg is not our friend. A viewer can find an image and have no idea where it came from. If they have dragged it to their desktop for future consideration then the task is even more difficult, unless the metadata was entered and is still there.
Here are two helpful tools to help with image identification.
1) Jeffrey Friedl’s EXIF viewer allows you to see inside any file, web or desktop, to see stored metadata, caption copyright date etc.
2) Tineye allows you to other occurences on the web of any image file, web or desktop, using visual recognition to match your images with those in its index.
An obvious question is why does Google (or Bing or Yahoo) not provide these services. None of these search engines look within an image file to read photo metadata. Certainly keywords and copyright info at a minimum would help with Image Search. And none of them can match candidate images using image recognition technology.