Flatten Annotations in Linux

Information

PSPDFKit Processor has been deprecated and replaced by PSPDFKit Document Engine. All PSPDFKit Processor licenses will work as before and be supported until 15 May 2024 (we will contact you about license migration). To start using Document Engine, refer to the migration guide. With Document Engine, you’ll have access to robust new capabilities (read the blog for more information).

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.

Before you get started, make sure Processor is up and running.

You can download and use either of the following sample documents for the examples in this guide:

You’ll be sending multipart POST requests with instructions to Processor’s /build endpoint. To learn more about multipart requests, refer to our blog post on the topic, A Brief Tour of Multipart Requests.

Check out the API Reference to learn more about the /build endpoint and all the actions you can perform on PDFs with PSPDFKit Processor.

To flatten a PDF document, apply the flatten action to the PDF part in the /build endpoint’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/build \
  -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 /process HTTP/1.1
Content-Type: multipart/form-data; boundary=customboundary

--customboundary
Content-Disposition: form-data; name="document1"; filename="example-document1.pdf"
Content-Type: application/pdf

<PDF data>
--customboundary
Content-Disposition: form-data; name="document2"; filename="example-document2.pdf"
Content-Type: application/pdf

<PDF data>
--customboundary
Content-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 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/build \
  -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 /process HTTP/1.1
Content-Type: multipart/form-data; boundary=customboundary

--customboundary
Content-Disposition: form-data; name="document"; filename="example-document.pdf"
Content-Type: application/pdf

<PDF data>
--customboundary
Content-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--