Efficiently linearize PDFs on Linux with Document Engine

Information

PSPDFKit Processor has been deprecated and replaced by Document Engine. 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).

You can linearize PDFs using PSPDFKit Processor.

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.

PDF Linearization

A linearized PDF file is organized in a special way to enable efficient incremental access in a network environment. Enhanced viewer applications can recognize that a PDF file has been linearized and take advantage of that organization.

To linearize a PDF, use the following example:

curl -X POST http://localhost:5000/api/build \
  -F document=@/path/to/example-document.pdf \
  -F instructions='{
  "parts": [
    {
      "file": "document"
    }
  ],
  "output": {
    "type": "pdf",
    "optimize": {
      "linearize": true
    }
  }
}' \
  -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"
    }
  ],
  "output": {
    "type": "pdf",
    "optimize": {
      "linearize": true
    }
  }
}
--customboundary--

Licensing

To linearize PDFs with PSPDFKit Processor, the Linearization feature needs to be included in your license. Contact Sales to add linearization to your license. After the new component is added to your license, update the offline LICENSE_KEY in your PSPDFKit Processor configuration.

Other Types of PDF Compression

You can perform both linearization and compression in a single request to /build if both features are enabled in your license:

instructions = {
  ...
  output: {
    type: "pdf",
    optimize: {
      grayscaleText: true,
      grayscaleGraphics: true,
      grayscaleFormFields: true,
      grayscaleAnnotations: true,
      disableImages: true,
      mrcCompression: true,
      imageOptimizationQuality: 2,
      linearize: true,
    }
  }
}

To learn more about other types of compression supported by PSPDFKit Processor, refer to the PDF compression guide.