Scanned PDF files? If you haven’t used a scanner before, it’s simply a PDF that’s been optically scanned and turned into a digitized replica of the original paper file. The obvious benefit of doing so is that once digitized it … Continue reading →

A watermark is a recognizable image or pattern in paper that appears as various shades of lightness/darkness when viewed by transmitted light (or when viewed by reflected light, atop a dark background), caused by thickness or density variations in the … Continue reading →

PDF files can be created specifically to be accessible for disabled people. Current PDF file formats can include tags (XML), text equivalents, captions, audio descriptions, et cetera. Some software can automatically produce tagged PDFs, however this feature is not always … Continue reading →

AcroForms can keep form field values in external stand-alone files containing key:value pairs. The external files may use Forms Data Format (FDF) and XML Forms Data Format (XFDF) files. The usage rights (UR) signatures define rights for import form data … Continue reading →

A PDF document may be protected by password to open (‘user’ password) and the document may also specify operations that should be restricted even when the document is decrypted: printing, copying text and graphics out of the document, modifying the … Continue reading →

There are many people want to add page numbers to PDF files, bottom of PDF pages as below. Q1: Putting Page Numbers on a pdf I’d like to add page numbers. Is it possible in Acrobat 8.0? I didn’t write the pdf, … Continue reading →

The standard security provided by Acrobat PDF consists of two different methods and two different passwords, “user password” and “owner password”. A PDF document may be protected by password to open (‘user’ password) and the document may also specify operations … Continue reading →

All operations (except the document open password protection, if applicable) which are restricted by “owner” or “user” passwords are trivially circumvented by many commonly available “PDF cracking” software and even freely online, and if circumvented these restrictions no longer let … Continue reading →

The Microsoft Reader .LIT file format is a modification of the HTML Help CHM format. CHM files are sometimes used for e-books.  Sumatra PDF supports viewing CHM documents since version 1.9.

A new version of PDF standard is under development under the name ISO/CD 32000-2 – Document management—Portable document format—Part 2: PDF 2.0 (as of July 2011). PDF 2.0 was accepted by ISO as a new proposal. Anyone may create applications … Continue reading →