Chapter 10

cpdf -list-annotations in.pdf [<range>]

cpdf -list-annotations-json in.pdf [<range>]

cpdf -set-annotations-json <filename> [-underneath]
     in.pdf [<range>] -o out.pdf

cpdf -copy-annotations from.pdf to.pdf [<range>] -o out.pdf

cpdf -remove-annotations in.pdf [<range>] -o out.pdf

10.1 Listing Annotations

The -list-annotations operation prints the textual content of any annotations on the selected pages to standard output. Each annotation is preceded by the page number and followed by a newline. The output of this operation is always UTF8.

cpdf -list-annotations in.pdf > annots.txt

Print annotations from in.pdf, redirecting output to annots.txt.

More information can be obtained by listing annotations in JSON format:

cpdf -list-annotations-json in.pdf > annots.json

Print annotations from in.pdf in JSON format, redirecting output to annots.json.

This produces an array of (page number, object number, annotation) triples giving the PDF structure of each annotation. Destination pages for page links will have page numbers in place of internal PDF page links, but the content is otherwise unaltered. Here is an example entry for an annotation with object number 102 on page 10:

  10, 102
  { "/H": { "N": "/I" },
    "/Border": [ { "I": 0 }, { "I": 0 }, { "I": 0 } ],
    "/Rect": [
      { "F": 89.88023 }, { "F": 409.98401 }, { "F": 323.90561 }, {
        "F": 423.32059 } ],
    "/Subtype": { "N": "/Link" },
    "/Type": { "N": "/Annot" },
    "/A": {
      "/S": { "N": "/URI" },
      "/URI": { "U" : "" },
    "/StructParent": { "I": 10 } }

Extra objects required for annotations, but which are not annotations themselves are also extracted. They omit the page number, being just a pair of the object number and object. The CPDFJSON format is described on page 109. There is an additional object, -1, which gives the CPDF annotation format version, currently 1.

10.2 Setting annotations

We can also set annotations from a JSON file, either modified from the output of -list-annotations-json or produced manually:

cpdf -set-annotations annots.json in.pdf -o out.pdf 

Add the annotations in annots.json on top of any already present in in.pdf, writing to out.pdf.

If replacing rather than adding annotations, use -remove-annotations first to clear the existing ones.

10.3 Copying Annotations

The -copy-annotations operation copies the annotations in the given page range from one file (the file specified immediately after the option) to another pre-existing PDF. The range is specified after this pre-existing PDF. The result is then written an output file, specified in the usual way.

cpdf -copy-annotations from.pdf to.pdf 1-10 -o result.pdf 

Copy annotations from the first ten pages of from.pdf onto the PDF file to.pdf, writing the result to results.pdf.

It exists for historical reasons, and is no different from listing and setting the annotations using -list-annotations-json and -set-annotations.

10.4 Removing Annotations

The -remove-annotations operation removes all annotations from the given page range.

cpdf -remove-annotations in.pdf 1 -o out.pdf

Remove annotations from the first page of a file only.