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I learned about digital photography metadata from the FBI. They didn't give me a course or anything; they sent out a news release years ago that terrorists may be sending messages encoded into pictures on the Internet. As far as I know, your dgital camera isn't serving Al Qaeda's ends, but it did let me to discover that there's a whole world of information in a JPEG beyond the pictures you see.
You probably know what metadata is -- we use it all the time now, whether putting track names on an MP3 or looking up a library book by its Dewey Decimal number. You may even have used it on your photos, tagging a shot of the beach as "vacation." But it can be staggering to learn how much information there actually is.
Example: This is a JPEG:
But this is the information inside. The shutter speed, the aperture, user-added tags, even latitiude and longitude, they're all in there. Don't worry, though -- people can't find out your address from your online photos unless you want them to, or unless you're careless. There are two groups of metadata important to understand -- EXIF and IPTC. Broadly speaking, EXIF is what is captured on the image at the time you shot it, and IPTC are all the user-added comments afterward. Your EXIF knows what the camera was doing -- when the picture was taken, how fast the shutter went, what lens you used, etc., but it doesn't know that you were taking a picture of your aunt. That's for you to add.
What good is metadata? It's hard to even scratch the surface of the possibilities, but two major benefits are organization and improving your craft by figuring out how other people took photos you enjoy. The benefits for organization are obvious to anyone who's ever tried to sort through a basement full of negatives. The different between sorting through a box that says "Mid-80s" and being able to zoom in on photos you took on April 12 is palpable. If you take advantage of programs that can add metadata -- from free programs like Apple's iPhoto to professional software like Adobe Lightroom -- you can be as organized as you want. Maybe you want to note all of the people in the photos you take. Maybe you're into color and want to track which photos were dominantly red, and which were dominantly green. Maybe you want to track all the photos you took in Hawaii -- whatever you want, the notes affix themselves to the photo, so you'll have them wherever you store it.
But there's more. This is the Web 2.0 age, a time of unprecedented sharing. You don't have to ask a photographer "Hey, what camera did you use to take this?" If you can see the EXIF, you'll know, along with what focal length, ISO, shutter speed and aperture he or she used to make the photo look the way it does. Sites like Flickr or Picasa Web Albums have the EXIF available for public viewing on every photo (at the photographer's discretion), and they can be a great course in learning exactly what sorts of images these parameters can create. Sure, you can know intellectually that a long focal length lens plus a wide aperture equals a shallow range of focus, but isn't it easier to see it?
Here's the EXIF for this image.What does it tell us? The shallow focus comes from the combination of focal length (85mm), aperture (f/1.4) and distance (not shown, but about 15-20 feet). The shutter speed had to be 1/100th to freeze motion (and that was pushing it; faster would have been better if possible), and the ISO had to be bumped up to 1600 to allow that shutter speed to happen indoors. You can learn a lot about a photographer's choices from looking through EXIF.
So what can't you learn? In advanced photography, actually snapping the shutter is the least difficult part -- it's getting to the spot where the picture happens that matters. Either that's a physical journey to exotic locales, the sidelines of the big game, waiting for the perfect sunset, setting up studio lights, or simply getting your subject to react to you in an attractive way. EXIF won't help you there.
Take this photo:
This was taken at 102mm at f/13 and ISO 100. We can learn a few things about the photographer's choices from there -- it's attractively proportioned because of a long focal length, the small aperture and low ISO meant standard room light would be totally black, so this was lit by bright flashes, but we can't go out and recreate this photo just knowing those settings. And that's just a studio shot -- EXIF certainly isn't going to get you a gorgeous shot of the Hindu Kush mountains. Because of that, I hope that photographers are more free with letting their EXIF show on Web-based photos so beginners and intermediate students can learn valuable things about the mechanics of a shot. It's a great way to learn Photography 101, especially for the visually-oriented people who become photographers, but it's not going to cost the pros their jobs.
--Ryan Brenizer
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Now consider...
In measurement science, analytical chemistry in particular, data are "converted" into pictures in at least two major ways. First, and most obvious, is they are presented as images called photographs and videos. Second, and perhaps less directly obvious are the pictures of data that we scientists would normally call spectra. In both cases, one can imagine the same metadata as described in this article "enhancing" the photographs and videos taken. It could include all instrumental parameters needed to obtain the image. Moreover, standard operating procedures (SOP's), sample preparation, chain of custody, and every datum necessary to establish the pedigree of the sample studied could be directly embedded with the data of the spectra. Indeed, the entire analyst report could be part of the photograph, video, or spectrum.
Today, we consider such data as parts of reports. The emphasis is on the written word and each written report may contain or reference several images, videos, or spectra that enhance an author's point within a specific passage of a report. My questions are... can we do better and is this approach always the best?
Images, whether they are photographs, videos, or spectra make a powerful impact on the viewer. Indeed, the truism that a picture states a thousand words is unrefuted. Why then, as scientists, do we cling to burying such powerful media in written reports. I think there is a better way.
Consider Amazon again for a moment. When you search for a book, you are presented an emphasis on the image of the book, the title and, lately, hovering over images of books bring a list of links leading you to more information, much of it text but, potentially, some of it more imagery. Amazon does not bury the image of the book within the bounds of prose that might describe the book.
So how would such work in science? Imagine that instead of the National Transportation Safety Committee (NTSC) publishing a long report on an accident that includes a few pictures, it chose one image that highlights a particular aspect of the investigation, or the entire investigation, creates links and metadata within those images that reference and cross-reference items in the report. The table of contents could be a series of images followed by one line of text and the reader would quickly connect with the contents through the powerful imagery being presented.
Many other examples can be imagined. Databases emphasizing image based content already exist with the inclusion of chemical structures, spectra thumbnails, etc. Scientific journals are starting to include images as part of their web-based table of contents, but does this go far enough in encouraging authors to emphasize image-based authoring? Show a spectrum and embed the report rather that the other way around. Relative to publishers, research labs in the chemical and petrochemical industry are lagging significantly in this regard with little capability today on content management, knowledge management, and multimedia publishing systems to enable these approaches. As multimedia publication becomes cheaper, ubiquitous, and more flexible, should we consider the traditional scientific publication format passe?
I hope to have time in the future to create some specific examples emphasizing some of the advantages that I envision such a approach to have.
