PDF Linearization is a way of optimizing PDFs so they can be streamed into a client application in similar to videos. This helps remote, online documents open almost instantly, without having to wait minutes for a large document to completely download.
Linearization is thus especially useful when accessing large documents from any remote URL or resource, be it from a browser, mobile, desktop or server application.
eViewer supports Linearized PDF, and users will benefit from having PDFs linearized. It is also a simple matter to create linearized documents using either using the in-built functions available with eViewer’s server app or using a third-party tool.
Linearization, introduced with PDF 1.2, has a 20+ page appendix dedicated to it in the core PDF reference.
But if you prefer a faster and quicker explanation…
Linearization works by modifying the PDF file’s internal structure that enables fast on-demand streaming of partial content.
By linearizing, each PDF document transforms into an object tree, starting with a root node, and ascending from there. Pages can reference other objects located on that tree by object number. In the case of non-linearized PDFs, these objects, such as embedded fonts, are often scattered across the file. Therefore, with non-linearized PDFs, there are no quick methods to identify and grab a given page’s resources, most document viewers will need to download the entire document before it can render.
In contrast, linearized PDFs are reorganized so that page resources are grouped together logically according to document page order. A Linearization Dictionary and “Hint tables” are also added to the top of the document. These act as an inventory specifying the location of objects needed to render any given page, essentially enabling random online access to pages.
A viewer designed to handle linearized content, like eViewer, can then request linearized PDF content from the web server via a URL. This information is then served as sequential content “packets” of PDF binary.
When eViewer detects linearization, it will stop the rendering process after receiving the hint tables and first few pages. Remaining content packets are then prioritized based on how the user navigates. For example: if the user skips ahead to page 750 in a 2000-page document, the viewer can request resources for page 750 and surrounding pages, and these will render first. The remainder of the document will then progressively download and render as the user session continues. And unneeded pages can be easily cleared from the device’s memory when required.
Any organization working with large, network-bound documents should consider using linearization to improve PDF files.
With more and more people working remotely, either out in the field or at home, having ideal network bandwidth isn’t possible. During our testing, as well as our clients, that linearized PDFs enables displaying of 50 MB PDFs in just under 7 seconds with average residential highspeed internet or using a 4G connection. Linearization, therefore delivers a much faster online experience overall. And it provides several other advantages when working with documents:
Linearization works by modifying the PDF file’s internal structure that enables fast on-demand streaming of partial content.
Linearizing PDF documents are not always beneficial to your organization and your users. A few things may cancel the advantages of linearizing PDF documents:
eViewer v7 was designed to take full advantage of linearized PDF documents to deliver documents quickly to any device (workstations, tablets, smartphones). Edit, annotate, and redact PDF documents, both linearized and non-linearized, easily. Not only can eViewer display PDF documents, it can also display TIFF, MODCA, MS Office, and more.
Check out the eViewer website for a more in-depth review of the latest HTML5 viewer as well as a live demo to try it for yourself. If you’re ready to get started with an evaluation, you can contact us now to discuss testing the eViewer in your environment.
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