In this post, we’ll take a look at what image metadata is, its performance impacts, some security concerns you might not be aware of, along with details on how to scrub metadata from your images.
Images account for a whopping 50% of the total file size of a web page. But consider this: On average, image metadata makes up 16% of a typical JPEG file on the web, according to website optimization service Dexecure. This means 8% of what we download online is useless, unnecessary metadata.
What is Image Metadata?
Metadata is generally described as data about data. Image metadata, specifically, is information embedded into an image that includes details about the image itself as well as information about how it was created.
In addition to visual data, image files actually contain several different formats for metadata, which in turn store different types of information:
- EXIF (Exchangeable image file format) – Information generated automatically by the device that captured the image (i.e. cameras and smartphones), such as data and time, and camera settings (make and model, image orientation, aperture, shutter speed, focal length, metering mode, ISO speed etc). This specification also helps cameras use formats that can be exchanged between devices; for example, ensuring an iPhone photo appears correctly on a Samsung device.
- IPTC (International Press Telecommunications Council) – A format originally adopted by old media news agencies to streamline information, but has been implemented by new media to do much the same thing. The IPTC section of an image usually contains information about the image, such as title, description, keywords, photographer’s information, copyright restrictions, and more.
- XMP (Extensible Metadata Platform) – An XML-based format recently adopted by Adobe that incorporates all the information from the IPTC format, but allows for additional information to be stored within the image
- 8BIM – A file extension used by Photoshop that stores some graphics-related data.
- ICC (International Color Consortium) – In color management, an ICC profile is a set of data that characterizes a color input or output device, or a color space, according to standards set by the ICC. Imaging programs like GIMP use ICC color profiles to interpret an image’s RGB values.
- Image metadata allows information to be transported together with an image, in a way that can be understood by software, hardware, and humans, regardless of the format.
While some metadata is generated by manufacturers and devices that capture images, other metadata may be added manually and edited using software like GIMP and Photoshop.
A lot of information can be contained in metadata—There are more than 460 metadata tags alone for the EXIF format.
Removing Image Metadata on Windows
Windows Explorer makes it easy to delete EXIF information from a single photo or a batch of photos in one go. Just follow these steps:
- Select all the files you want to delete metadata from.
- Right-click anywhere within the selected fields and choose “Properties.”
- Click the “Details” tab.
- At the bottom of the “Details” tab, you’ll see a link titled “Remove Properties and Personal Information.” Click this link.
- Windows will ask whether you want to make a copy of the photo with this information removed, or if you want to remove the information from the original. Choose the option you prefer and click “OK.