About PDFlib PLOP

PDF Linearization, Optimization and Protection.

PDFlib PLOP is a versatile tool which can repair, linearize, optimize, encrypt, and decrypt PDF documents. PLOP linearization and optimization features create efficient and small PDF documents for fast Web delivery. PLOP protection features encrypt or decrypt PDF documents and apply or remove permission settings, such as »printing not allowed« or »content extraction not allowed«. The PLOP repair mode automatically detects damaged PDF documents and fixes the problems if possible. PLOP analysis features can be used to query arbitrary properties of a PDF document. In addition, document metadata can be retrieved and set.

PDFlib PLOP (PDF Linearization, Optimization, Protection) offers a straightforward way to linearize and optimize your PDF files for fast Web delivery, and to apply or remove Acrobat security features. PDFlib PLOP DS (Digital Signature) offers all features of PLOP, plus the ability to apply digital signatures to PDF documents.

With PDFlib PLOP you can linearize a PDF document for fast delivery over the Web (byteserving). Byteserving increases the perceived download speed since the first page is already visible while the remainder of the document is downloaded in the background.

Optimization. PLOP can significantly reduce the file size of a PDF document without affecting quality. It achieves this by removing unnecessary or redundant identical objects, such as repeatedly embedded fonts, images, identical ICC color profiles, etc.

Repair Mode. Several kinds of damaged PDF documents are detected and automatically repaired, if possible.

Protection. PLOP can apply user and master passwords, and set access permissions to prevent the document from being printed with Acrobat, disallow text extraction or modification, etc. PLOP uses RC4 or AES encryption. AES encryption has been introduced in Acrobat 7, and is considered secure. Using PLOP’s protection features you can:

  • Encrypt a PDF document with user or master password, or both
  • Remove PDF encryption (if you know the master password)
  • Add or remove permission settings, e.g. »printing not allowed« or »text extraction not allowed« (if you know the master password)
  • Query information about the security status (encrypted with user or master password), encryption scheme, permission settings, and document info fields

Document Metadata. PLOP can read and set document info entries. In addition, it supports the automatic synchronization of XMP metadata.

Analysis. The PLOP library includes the pCOS interface for querying details about a PDF document, such as font lists, metadata, page size, and many more (see datasheet for the pCOS product).

PLOP Library and Command-Line Tool
PLOP is available as a programming library (component) for various development environments, and as a command-line tool for batch operations. Both offer similar features, but are suitable for different deployment tasks.

Supported Development Environments
PDFlib PLOP is everywhere – it runs on practically all computing platforms. PDFlib offer variants for all common flavors of Windows, Mac OS, Linux and Unix, as well as for IBM eServer iSeries and zSeries systems. (Please contact ComponentSource if the machine type price option you require is not listed)

The PLOP core is written in highly optimized C code for maximum performance and small overhead. Via a simple API (Application Programming Interface) the PLOP functionality is accessible from a variety of development environments:

  • COM for use with VB, ASP, Borland Delphi, etc.
  • C and C++
  • Java, including servlets and Java Application Server
  • .NET for use with C#, VB.NET, ASP.NET, etc.
  • Perl
  • PHP hypertext processor
  • RPG for use with iSeries

PDFlib PLOP DS (Digital Signature) offers all features of PLOP, plus the ability to apply digital signatures to PDF documents.

The signatures can be validated in Adobe Acrobat and Adobe Reader, without the need for any additional software. Signatures can be created from digital IDs in the common PKCS#12 and PFX certificate formats. On Windows digital IDs from the Windows certificate store can also be used.

Creating Digital Signatures with PDFlib PLOP DS. PDFlib PLOP DS (Digital Signature) offers all features of PLOP, plus the ability to apply digital signatures to PDF documents.

  • PLOP DS can apply standard PDF signatures which can be verified with Adobe Reader or Acrobat 6 and above. Signature support is available in the PLOP DS library and in the command-line tool, and works as follows:
  • PLOP DS reads certificates (digital IDs) from standard PKCS#12 or PFX files. On Windows, the certificate store can also be accessed to use certificates which are installed in the system.
  • PLOP DS can create signatures in existing signature fields or generate new fields to hold the signature. The generated signatures can be invisible, or visible at a particular location on the page. Several signature properties which will be displayed in Acrobat can be specified, such as the reason of the signature, location, contact info, etc.
  • PLOP DS supports all PDF versions up to and including PDF 1.7, the file format of Acrobat 8. Applying a signature can be combined with encryption (user password, master password, or permissions).

For specialized applications the crypto engine built into PLOP DS can be replaced with a custom engine, e.g. to leverage cryptographic hardware or certified cryptographic software modules.

Other Benefits: PLOP is PDF/A-aware: if the input document conforms to the PDF/A standard, the output document is guaranteed to still comply with PDF/A. Similarly, PLOP is PDF/X-aware.

Since PLOP accepts PDF input documents from a disk file or directly in memory, it can easily be combined with PDFlib for dynamic PDF generation. For example, using the combination of PDFlib and PLOP DS you can create PDF invoices and sign them before sending them to the customer.