PDFlib PLOP (PDF Linearization, Optimization, Protection) is a versatile tool for linearizing, optimizing, repairing, analyzing, encrypting and decrypting 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«.
• PLOP’s 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.
• Document info entries and XMP metadata can be retrieved and set in a PDF/A-conforming manner.

Linearization. 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.

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 supports both the older RC4 encryption algorithm as well as the more secure AES algorithm. With 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

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

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

Document Info Entries. With PLOP you can add new document information entries or replace the values of existing info entries. Both predefined and custom entries can be set. If the input document contains XMP document metadata, all predefined info entries will automatically be synchronized to the XMP metadata in order to keep the metadata consistent (this is a requirement of PDF/A-1).