EXIF, IPTC and XMP Metadata
EXIF, IPTC and XMP metadata are additional information fields that are stored within an image file (such as a JPG) that provide additional information about the image.
EXIF metadata is information about the image recorded by a digital camera – for example, the exposure time and the date the photo was taken.
IPTC and XMP metadata is information about the image from the photographer, for example, captions or copyright
information. The IPTC standard is an older, international standard. More recently Adobe have published the XMP standard, which is used by a lot of image editing software.
You should make sure your images have the required IPTC/XMP metadata before uploading to your website.
When WordPress uploads images, it uploads the Full Size image unchanged and automatically creates several differently sized versions of the image. This means there are up to 4 versions of the image on your site, and only the Full Size original has metadata:
- Full Size version (metadata preserved)
- a Large version (no metadata)
- a Medium version (no metadata)
- a Thumbnail version (no metadata)
These different sized versions are used in different places including in your Gallery display – this displays the Thumbnails (in the scrolling list to the left) and the Large image (the single image display to the right), and clicking the Large image displays the Full Size.
More about IPTC, XMP and EXIF:
IPTC
IPTC for Copyright
XMP
EXIF
Viewing Metadata
With OSX Terminal you can use the mdls command: $ mdls filename.jpg. Also available on OSX is EXIF Viewer
If you are using Windows you can use this excellent online tool (which can be used on images from your hard disk or from any website):
Online EXIF Viewer.
