A caption is descriptive text that appears below an image. InDesign provides several methods for creating captions that display the image metadata you specify. InDesign provides a special caption variable that displays the specified metadata of an image. If a text frame containing the variable is next to or grouped with the image, the variable displays the metadata of that image. You can generate a caption from an existing image or while placing it, and you can create a text frame that contains a caption variable.
When you generate a caption from an existing image, you can generate either a static caption, which can be modified only manually, or a live caption, which is updated if the image or the image metadata changes. For example, if you move a live caption next to a different image, the caption displays metadata from the different image.
When you choose Generate Live Caption, a new variable is generated automatically based on the current caption settings. For example, if the Description metadata type is selected in the Caption Setup dialog box, a variable called “Live Metadata Caption: Description” is created.
When you generate a live caption that displays a long string of text, such as a Description, the caption does not break across lines because it is a variable. If a caption is compressed into a single line, consider converting a live caption to a static caption. To convert a live caption to a static caption, select the live caption and choose Object > Captions > Convert To Static Caption.
You can also generate a static caption while placing an image. In the Place dialog box, select Create Static Captions, and then place the caption text frame after placing the image.
Use the Captions Settings dialog box to determine the content and formatting of captions you generate. These captions affect only future captions you generate, not existing captions.
Specify a paragraph style to apply to the caption text. If you want the caption to include automatic numbering, such as “Figure 1,” “Figure 2,” and so on, include the numbering in the paragraph style. See Create running captions for figures and tables.
When a text frame containing a caption variable is adjacent to or grouped with an image, the caption variable displays the metadata of that image.
A. Text frame with caption variable not next to image B. Text frame moved next to image
If the caption variable is blank, edit the image metadata, and then use the Links panel to update the image. To edit image metadata, see Edit metadata in image files.
Caption variables are updated automatically when a text frame containing a caption variable is moved next to an image. By default, the Name metadata is used for the variable type when you choose Type > Text Variables > Insert Variable > Image Name. You can edit the Image Name variable, or you can create new variables that specify image metadata.