15.md

Import/Link to external resource

PDF/A version	Conformance level	Class type	Severity
1, 2, 3	bua	Conformance	5

The PDF/A document has links to an external resource instead of embedding it, such as, external file specifications and referenced XObjects.

Reproducibility

Edit

Example of the simple file with reference XObject:

1. Create PDF document with one page

2. Find /Page dictionary from /Catalog dictionary:

/Catalog -> /Pages -> /Kids -> /Page

3. Create new stream object which will be used as Reference XObject (for example 15 0 R)

Example of simple stream object:

15 0 obj
<</Length 0>>
stream

endstream
endobj

4. Add the key /XObject dictionary inside /Resources dictionary

Example:

/Resources <</XObject <</SomeName Link to object from step 3>>
Final ver.: /Resources <</XObject <</SomeName 15 0 R>>

Note: SomeName is the name of your XObject. This name would be used in Page content stream

4. Go to the object which was created at the step 3

5. Add the requied keys from table 95 (PDF32000) and key /Ref <</F Link to new object /Page 1>>

6. Create new dictionary object for Filespec dictionary

7. Add object number of the created dictionary for the key /F (e.g. 16 0 obj)

   /Ref <</F 16 0 R /Page 1>>

8. Go to new dictionary (16 0 obj)

9. Add keys /F (type string) and /Type /Filespec

   16 0 obj <</Type /Filespec /F (path to other file)>> endobj

For example: /F (//pdfdocs/spec.pdf)

10. Go to page content stream

11. Add the operator Do with name of the created XObject

For example:

5 0 obj
<</Length 25>>
stream
/SomeName Do
ednstream
endobj

12. Update length of content stream, xref table and trailer

Experimental Collection

Synthetic

• veraPDF test suite / PDFA-2 / veraPDF test suite: 6-2-9-2-t01-fail-a