What is metadata?

At the most basic level, metadata is data about data.

Artists and photographers who manage their own websites may be aware of the metadata that web pages can contain, but which is not normally visible to the viewer, such as a list of keywords, or a short description of the page contents, or a host of other more technical information which may also be present.

What many may be less aware of is that image files can also contain their own metadata, either because a camera put it there, an image editor put it there, or the artist put it there. This brief article is about the metadata that might be in your image files, which bits you might not want to be there, and most importantly which bits you might want to add! In the latter category are copyright information, and items useful for search engines.

what does a digital camera add?

A digital camera will add quite a lot of metadata to the image files it creates. This is likely to include camera settings, from basics of shutter speed and aperture, to a record of everything option currently set on the camera, current location (via GPS) and other information (possibly encrypted) specifically for the use of the manufacturer’s software. This information can amount to a significant portion of the file size of a small jpeg image, and in many cases is of no interest when the image is being used on a website – especially if the photograph is not the artwork itself.

The information stored by the camera itself is generally referred to as EXIF data.

what does editing software add?

This depends very much on the software in use, but some software may store details about settings used while manipulating the image. Its unlikely you want to have this in an image placed on the web.

what might you want to add?

This is the important bit! None of the above identifies you, what the image is actually of (its title, perhaps), terms of use, or anything to do with your rights over the image. This is the information that you probably actually want to have associated with the image if someone takes a copy from a website.

This can be added to the image data in a section known as the IPTC metadata.

Managing metadata

How you manage metadata will depend on the editor you are using. I only use a limited number of tools so can only give outline guidance on how to add or remove it. First though, lets address why you would want to add or remove it, before going on to the question of how to do it.

Why remove metadata

The biggest reason for removing metadata is to reduce the size of your image files on the internet. Some camera manufacturers store a relatively large amount of EXIF data in the image files. (Small in relation to a 10 Mpixel raw file, but large in relation to a medium compression 500×300 pixel jpeg web image). If you’ve got a busy website, or your images are stored on a third party stock or shop site having (hopefully) lots of people downloading this unnecessary data puts needless strain on the bandwidth available to your (or more likely their) webservers. It makes sense to not keep transmitting unwanted data across the network.

There may also be other data stored in your images that you would not like publicised – GPS data for a rare plant (or antique) for instance.

Why add data?

As mentioned above, the main reason for adding metadata will be to identify you as the owner, provide a means of contacting you, and a name for the art. You might also want to add some sort of catalogue reference number so you can more easily find the original from the uploaded thumbnail.

a slight side trip

Adding metadata will not deter the determined image thief, as they can remove it as easily as you can add it, but it will help a picture researcher to locate you when an image file has been passed around a few times and the original source forgotten. It will also be of some help if the ‘orphan works’ legislation gets passed in the US (and possibly similar bills later in other countries).

Also, don’t think that tricks like pasting a clear gif image over your image file on a web page, or using flash to display images, will protect your images from being copied from a web page – they won’t. If it can be seen on a web page, it can be copied.

How to change the metadata

This is going to depend on what image editting software you have, so you’ll have to look in the manual.

For Adobe Photoshop the metadata can be editted using the ‘File Info’ menu item, probably in different places in different versions. For Lightroom there’s a panel in the library module.

When you save a jpeg file there may be options to minimise the metadata included, or to ‘save for web’ – check what these do – it may leave in exactly what you want, or it may remove too much. When you upgrade to a new version check again.

Possible problems

One problem I’ve seen is third party sales sites removing ALL the metadata in your file when they publish it on their site. They won’t tell you in advance that they are going to do this. If this happens you have two main options:

• accept it, and risk your image circulating on the internet with no identification (and so potentially free for anyone to use under the orphan works bill)
• find another sales outlet

You can try to persuade the site that it should not remove your copyright information without your permission (it may be illegal for them to do so), but you’ll probably find it difficult to get them to change their mind, unless other artists on the same site join you.

go to part 2 for considerations of search engine optimisation and image metadata.

This article was originally published, in a slightly different form, on Selected Artworks