PDFKit

⚠️ Warning: Experimental Phase

This library is currently in an experimental phase. APIs are subject to change without notice, and features may not be fully stable. Use with caution in production environments.

PDFKit is a comprehensive, pure Go library for PDF manipulation, designed to support the full spectrum of PDF standards from PDF 1.0 to PDF 2.0, including PDF/A, PDF/X, PDF/UA, and PDF/VT.

Features

Core Syntax & Structure

• Full Version Support: Read and write PDF 1.0 through PDF 2.0.
• Advanced Structures: Object streams, cross-reference streams, hybrid references, and linearization (Fast Web View).
• Incremental Updates: Modify files without invalidating existing signatures.

Graphics & Imaging

• Color Spaces: DeviceGray, DeviceRGB, DeviceCMYK, Lab, ICCBased, Separation, DeviceN, and NChannel.
• Patterns & Shading: Tiling patterns and all shading types (1-7), including tensor-product patch meshes.
• Images: Full support for image dictionaries, masks, soft masks (SMask), and inline images.
• Transparency: All 16 blend modes, transparency groups (isolated/knockout), and soft masks.

Fonts & Text

• Format Support: TrueType, Type 1, Type 3, OpenType (CFF/TTF), and CID-Keyed fonts.
• Unicode: Full ToUnicode CMap support for text extraction.

Interactivity & Forms

• Annotations: Full support for all standard annotation types (Text, Link, Widget, 3D, Redact, etc.).
• Forms: AcroForms, XFA (XML Forms Architecture), and HTML Forms.
• Actions: JavaScript, GoTo, Launch, RichMedia, and more.

Compliance & Security

• PDF/A: Support for PDF/A-1, A-2, A-3, and A-4 (Archiving).
• PDF/X: Support for PDF/X (Graphics Exchange).
• PDF/UA: Support for PDF/UA (Universal Accessibility).
• Encryption: RC4 (40/128), AES (128/256).
• Signatures: PKCS#7, PAdES, LTV (Long Term Validation).

Installation

go get github.com/wudi/pdfkit

Usage

Check the examples/ directory for usage examples, including:

• Merging and splitting PDFs
• Extracting text and images
• Adding watermarks
• Creating invoices
• Handling CJK fonts

Testing

OCR tests require Tesseract OCR to be installed. Please refer to the Tesseract OCR installation guide for instructions specific to your operating system.

Run the full test suite:

go test ./...

To run tests with native OpenJPEG support (requires libopenjp2):

go test ./... -tags openjpeg

License

This project is licensed under the MIT License. See the LICENSE file for details.