Is there a way to check if a PDF is linearized?

Technical Support WebViewer
1

WebViewer Version:10.12.1

Hi there

Is there a way to check if a PDF is linearized?

I would like to process the file separately if it is linearized and if it is not.

I read the documentation and guides, and although there was information about linearizing and saving, I couldn’t find any information on checking whether the PDF was linearized.

Thank you and best regards

2

Hello, I’m AiRon, an automated tech support bot :robot:
While you wait for one of our customer support representatives, I can help you with your question.


To check if a PDF is linearized, you can typically examine the PDF’s structure. Linearized PDFs have a special structure that allows them to be displayed incrementally, which is useful for web viewing. Apryse’s WebViewer doesn’t directly expose an API to check if a PDF is linearized, but you can infer it by examining how the PDF loads in a browser or by using a script to check the PDF structure.

Some things you can try:

  • Use an external library or tool to inspect the PDF file header for linearization hints.

  • Programmatically check for the presence of a linearization dictionary at the start of the PDF file.

  • Observe the loading behavior of the PDF; if it starts displaying before the entire file is downloaded, it might be linearized.



Here are some resources that might help you:


Hopefully, this helps you solve your problem while you wait for a human to get back to you.

3

Hi Harada,

I think this API is what you are looking for:

As this is a PDFNET API, you will have to enable fullAPI in your Webviewer constructor and make sure you initialize PDFNet:

await PDFNet.initialize();

const arrayBuffer = await file.arrayBuffer();

const doc = await window.Core.PDFNet.PDFDoc.createFromBuffer(arrayBuffer);
const isLinearized = await doc.isLinearized();

Let us know if that works for you.

Best Regards,
Mickaël.

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