PDF annotation flattening
Flattening is the process of embedding annotations in a PDF so that they can no longer be edited or removed. This leaves the visual representation of the annotations intact, but the annotations themselves are removed from the document.
- Ensure Document Engine is up and running.
- Send a multipart POST request(opens in a new tab) with instructions to Document Engine’s
/api/build
endpoint.
For more information, refer to the API reference to learn about the /api/build
endpoint and all the actions you can perform on PDFs with Document Engine.
For an overview of multipart requests, refer to the brief tour of multipart requests blog post.
To flatten a PDF document, apply the flatten
action(opens in a new tab) to the PDF part in the /api/build
endpoint(opens in a new tab)’s instructions. This request merges the document1
and document2
files before flattening the annotations in the final output PDF.
curl -X POST http://localhost:5000/api/build \ -H "Authorization: Token token=<API token>" \ -F document1=@/path/to/example-document1.pdf \ -F document2=@/path/to/example-document2.pdf \ -F instructions='{ "parts": [ { "file": "document1" }, { "file": "document2" } ], "actions": [ { "type": "flatten" } ]}' \ -o result.pdf
POST /api/build HTTP/1.1Content-Type: multipart/form-data; boundary=customboundaryAuthorization: Token token=<API token>
--customboundaryContent-Disposition: form-data; name="document1"; filename="example-document1.pdf"Content-Type: application/pdf
<PDF data>--customboundaryContent-Disposition: form-data; name="document2"; filename="example-document2.pdf"Content-Type: application/pdf
<PDF data>--customboundaryContent-Disposition: form-data; name="instructions"Content-Type: application/json
{ "parts": [ { "file": "document1" }, { "file": "document2" } ], "actions": [ { "type": "flatten" } ]}--customboundary--
Flattening Specific Pages of a Document
Flattening is applied to all parts(opens in a new tab) when it’s specified in the outermost actions
field. To flatten only a section of a document, split the document into multiple parts and flatten each part separately.
A part can be restricted to certain pages of a document. This way, you can flatten annotations only on the specified pages. The request below will flatten the first two pages of a four-page document with indexes from zero to four.
curl -X POST http://localhost:5000/api/build \ -H "Authorization: Token token=<API token>" \ -F document=@/path/to/example-document.pdf \ -F instructions='{ "parts": [ { "file": "document", "pages": { "start": 0, "end": 1 }, "actions": [ { "type": "flatten" } ] }, { "file": "document", "pages": { "start": 2, "end": 3 } } ]}' \ -o result.pdf
POST /api/build HTTP/1.1Content-Type: multipart/form-data; boundary=customboundaryAuthorization: Token token=<API token>
--customboundaryContent-Disposition: form-data; name="document"; filename="example-document.pdf"Content-Type: application/pdf
<PDF data>--customboundaryContent-Disposition: form-data; name="instructions"Content-Type: application/json
{ "parts": [ { "file": "document", "pages": { "start": 0, "end": 1 }, "actions": [ { "type": "flatten" } ] }, { "file": "document", "pages": { "start": 2, "end": 3 } } ]}--customboundary--