PDF is a complex format encompassing several technologies, from compression and cryptographic algorithms to image and typographic formats. Although nowadays lots of features are available, PDF Clown is still under development: the following table analytically describes its status based on PDF 1.7 specification.

NOTE — The numbers enclosed within square brackets (e.g. “[2]”) represent the priority level associated to a yet-to-implement feature, i.e. the relative importance of the feature, hence the likelihood for it to be chosen for the next development cycle. Priority levels range from 0 (lowest) to 5 (highest).
Section DONE % TODO
3. Syntax 72.5
3.1. Lexical conventions 100
3.2. Objects 100
3.3. Filters
  • 3.3.2. ASCII base-85
  • 3.3.3. Flate (zlib/deflate)
 25
  • [2] 3.3.1. ASCII Hex
  • [3] 3.3.3. LZW (Lempel-Ziv-Welch)
  • [3] 3.3.4. RLE (Run Length Encoding)
  • [3] 3.3.5. CCITT G3/G4
  • [3] 3.3.6. JBIG2 (Joint Bi-level Image experts Group)
  • [3] 3.3.7. JPEG/DCT (Discrete Cosine Transform)
  • [3] 3.3.8. JPEG2000 (Joint Photographic Experts Group)
3.4. File structure
  • 3.4.1. File Header
  • 3.4.2. File Body
  • 3.4.3. Cross-Reference table
  • 3.4.4. File Trailer
  • 3.4.5. Incremental Updates
  • 3.4.6. Object Streams
  • 3.4.7. Cross-Reference Streams
 95
  • [2] 3.4.7. Compatibility with PDF 1.4 (hybrid-reference file)
[2] 3.5. Encryption 0
3.6. Document structure 87.5
3.7. Content Streams and Resources 95
3.8. Common Data Structures
  • 3.8.1. Text Strings
  • 3.8.3. Dates
  • 3.8.4. Rectangles
  • 3.8.5. Name Trees
  • 3.8.6. Number Trees
 90
  • [2] 3.8.2. Text Streams
[4] 3.9. Functions 50
[3] 3.10. File Specifications 90
4. Graphics 70
4.1. Graphics Objects
  • Text objects
  • External objects
  • Inline image objects
  • Path objects
  • Shading objects (partial)
 90
  • [3] Shading objects
4.2. Coordinate Systems 100
4.3. Graphics State
  • 4.3.1. Graphics State Stack
  • 4.3.2. Details of Graphics State Parameters
  • 4.3.3. Graphics State Operators
  • 4.3.4. Graphics State Parameter Dictionaries
 90
4.4. Path Construction and Painting 100
4.5. Color Spaces
  • 4.5.1. Color Values
  • 4.5.2. Color Spaced Families
  • 4.5.3. Device Color Spaces
  • 4.5.4. CIE-Based Color Spaces (partial)
  • 4.5.5. Special Color Spaces (partial)
  • 4.5.7. Color Operators
 60
  • [3] 4.5.4. CIE-Based Color Spaces
  • [3] 4.5.5. Special Color Spaces
  • [0] 4.5.6. Overprint Control
[2] 4.6. Patterns 35
4.7. External Objects 80
  • [1] 4.7.1. PostScript XObjects
4.8. Images
  • 4.8.1. Image parameters
  • 4.8.2. Sample Representation
  • 4.8.3. Image Coordinate System
  • 4.8.4. Image Dictionaries
  • 4.8.6. Inline Images
 70
  • [1] 4.8.5. Masked Images
4.9. Form XObjects
  • 4.9.1. Form Dictionaries
 50
  • [2] 4.9.2. Group XObjects
  • [2] 4.9.3. Reference XObjects
4.10. Optional Content 100
5. Text 75
5.1. Organization and Use of Fonts
  • 5.1.1. Basics of Showing Text
  • 5.1.2. Achieving Special Graphical Effects
  • 5.1.3. Glyph Positioning and Metrics
 100
5.2. Text State Parameters and Operators
  • 5.2.1. Character Spacing
  • 5.2.2. Word Spacing
  • 5.2.3. Horizontal Scaling
  • 5.2.4. Leading
  • 5.2.5. Text Rendering Mode
  • 5.2.6. Text Rise
 90
  • [3] 5.2.7. Text Knockout
5.3. Text Objects
  • 5.3.1. Text-Positioning Operators
  • 5.3.2. Text-Showing Operators
  • 5.3.3. Text Space Details
 100
5.4. Introduction to Font Data Structures 100
5.5. Simple Fonts
  • 5.5.1. Type 1 Fonts – Standard Type 1 Fonts
  • 5.5.2. TrueType Fonts
  • 5.5.5. Character Encoding
 60
  • [1] 5.5.1. Type 1 Fonts – Multiple Master Fonts
  • [3] 5.5.3. Font Subsets
  • [1] 5.5.4. Type 3 Fonts
5.6. Composite Fonts 90
  • [1] 5.6.4 Predefined CMaps
5.7. Font Descriptors 95
  • [1] 5.7.2. (Font Descriptors for CIDFonts) Style, FD
5.8. Embedded Font Programs
  • CIDFontType2
 75
  • [1] Type 1
  • [2] CIDFontType0
[5] 5.9. Extraction of Text Content 80
[2] 6. Rendering 0
[1] 7. Transparency 0
7.2. Basic Compositing Computations
  • 7.2.4. Blend Mode
 10
7.3. Transparency Groups 0
7.4. Soft Masks 0
7.5. Specifying Transparency in PDF 0
7.6. Color Space and Rendering Issues 0
8. Interactive Features 65
8.1. Viewer Preferences 90
  • Prepress-related entries (ViewArea, ViewClip, PrintArea, PrintClip)
8.2. Document-Level Navigation
  • 8.2.1. Destinations
  • 8.2.2. Document Outline
 70
  • [0] 8.2.3. Thumbnail Images
  • [3] 8.2.4. Collections
[4] 8.3. Page-Level Navigation
  • 8.3.1. Page Labels
  • 8.3.2. Articles
  • 8.3.3. Presentations
 80
  • 8.3.3. Presentations: Sub-page Navigation
[4] 8.4. Annotations
  • Text annotations
  • Link annotations
  • Free text (callout) annotations
  • Line annotations
  • Square and circle annotations
  • Polygon and polyline annotations
  • Text markup annotations
  • Caret annotations
  • Rubber stamp annotations
  • Ink (scribble) annotations
  • Popup annotations
  • File attachment annotations
  • Sound annotations
  • Movie annotations
  • Screen annotations
  • Widget annotations
 80
  • Printer’s mark annotations
  • Trap Network annotations
  • Watermark annotations
[4] 8.5. Actions
  • Go-To actions
  • Remote Go-To actions
  • Embedded Go-To actions
  • Launch actions
  • Thread actions
  • URI actions
  • Sound actions
  • Movie actions
  • Hide actions
  • Named actions
  • Set-OCG-State actions
  • Rendition actions
  • Transition actions
  • Go-To-3D-View actions
 90
[5] 8.6. Interactive Forms
  • 8.6.1. Interactive Form Dictionary
  • 8.6.2. Field Dictionaries: Field Names, Variable Text
  • 8.6.3. Field Types: Button Fields, Text Fields, Choice Fields
  • 8.6.4. Form Actions
 50
  • 8.6.1. Interactive Form Dictionary
  • 8.6.2. Field Dictionaries: Rich Text Strings
  • 8.6.3. Field Types: Signature Fields
  • 8.6.5. Named Pages
  • 8.6.6. Forms Data Format
  • 8.6.7. XFA Forms
[2] 8.7. Digital Signatures 0
[1] 8.8. Measurement Properties 0
9. Multimedia Features 20
[2] 9.1. Multimedia 90
[1] 9.2. Sounds 0
[1] 9.3. Movies 0
[2] 9.4. Alternate Presentations 0
[2] 9.5. 3D Artwork 0
10. Document Interchange 20
10.1. Procedure Sets 100
10.2. Metadata
  • 10.2.1. Document Information Dictionary
  • 10.2.2. Metadata Streams
 100
10.3. File Identifiers 100
10.4. Page-Piece Dictionaries 100
10.5. Marked Content 100
[3] 10.6. Logical Structure 0
[3] 10.7. Tagged PDF 0
[3] 10.8. Accessibility Support
  • 10.8.1. Natural Language Specification: Language Identifiers
 10
  • 10.8.1. Natural Language Specification: Language Specification Hierarchy, Multi-language Text Arrays
  • 10.8.2. Alternate Descriptions
  • 10.8.3. Replacement Text
  • 10.8.4. Expansion of Abbreviations and Acronyms
[1] 10.9. Web Capture 0
[1] 10.10. Prepress Support 0
[2] F. Linearized PDF 0

Your Comment