OPI Image Reference Specification

OPI producer (PostScript or direct PDF output) include several OPI comments to allow post processing solutions to replace content according to the comments. The “ALDImageFileName” comment is used by HELIOS ImageServer and other vendors to reference the linked files. In remote layout workflows the low-resolution files are often used with local disk path names, therefore the “ALDImageFileName” fails finding the linked content. As a second option, OPI solutions can use the “ALDImageID” comment to find the original linked file on the server. OPI producers should generate an “ALDImageID” OPI comment from the placed files.

Several producers generate the “ALDImageID” for placed TIFF files. This documentation explains how the “ALDImageID” can be found in TIFF, JPEG, and EPSF files for unmodified inclusion into the OPI comments.

How to find the data for the “ALDImageID” comment?

For TIFF files

The image reference is stored using a private TIFF tag:

For EPSF files (Mac EPSF and Binary EPS)

For JPEG files