Specifications

PDF2DTP® for InDesign® Manual - 48
PDF2DTP for InDesign - OPI
It is important to understand a term known as “OPI” which stands for “Open Prepress Interface”. This is where
a low-resolution image is placed on the document page as a “placement holder” for a higher resolution image
stored in a known location. The hi-res image, which is of course a much larger file, will be located and used
in place of the lo-res picture at print time. If an image in the PDF is available on disk then a link to it will be
created. If a PDF was generated with no OPI comments then the original image name and location will of
course be unknown. If you choose “Save Missing Images” from the PDF2DTP Preferences a preview file will
be conveniently created using the original name.
PDF2DTP for InDesign - Found Links
If the link to the original image is known, PDF2DTP will import the file. If the image cannot be located then it
will convert the lo-res picture preview stored in the PDF. A problem arises due to the fact that the preview is
comprised of only those pixels that are viewable within the picture box. If you were to locate and import the
original image then its offset in the picture box may change if the image dimensions are greater than the
picture box.
PDF2DTP for InDesign - Standard OPI Disabled at PDF Creation Time
Most PDFs are generated by an application where the Export PDF “Use OPI” setting is not turned on in which
case the PDF will not contain a name for the image. The link to the path location of the original image is
therefore unknown.
PDF2DTP for InDesign - Clipping Paths
If the original image exists it will be imported and the application will use the default Clipping Path for the
image (if one exists). If the image is missing, or no link exists, you can add a Clipping Path to the created
preview file by selecting the PDF2DTP “Clipping Paths” Preference.
If a conversion reveals a picture box where the image is not being shown properly, for example is only
partially displayed, the first trick to try is to examine the Clipping Path. This can be done in the application by
either editing the points of the path or by deleting the path altogether.