WIA Standards

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Chapter 4: Phase 1 - Data Format Specification

The Data Format phase establishes the foundation for all WIA-ART-001 interoperability. This chapter provides detailed technical specifications for file formats, metadata schemas, color management, and quality tiers that ensure digital artwork can be reliably created, exchanged, and preserved across any platform or tool that implements the standard.

Understanding these specifications is essential for developers building WIA-compliant applications. The format requirements balance comprehensive functionality with practical implementability, ensuring that both simple tools and sophisticated platforms can participate in the standardized ecosystem.

4.1 Supported File Formats

WIA-ART-001 supports a carefully selected set of file formats that together address the needs of different digital art workflows. Each format has specific requirements for compliance, ensuring consistent interpretation across implementations.

4.1.1 Raster Graphics

Table 4.1: Raster Format Requirements

Format	Use Case	Bit Depth	Requirements
PNG	Lossless, web, archival	8, 16-bit	ICC profile, metadata chunks
JPEG	Photos, web distribution	8-bit	Quality ≥85, EXIF 2.3+
TIFF	Archival, print	8, 16, 32-bit	Lossless compression only
WebP	Modern web	8-bit	Lossless mode for art

4.1.2 PNG Requirements

PNG (Portable Network Graphics) serves as the primary format for lossless digital artwork. All WIA-compliant implementations MUST support PNG with the following specifications:

{
  "format": "PNG",
  "version": "1.2",
  "compression": "deflate",
  "bitDepth": [8, 16],
  "colorType": ["truecolor", "truecolor-alpha"],
  "requiredChunks": {
    "iCCP": "ICC color profile (REQUIRED)",
    "iTXt": "UTF-8 metadata (REQUIRED)",
    "tEXt": "ASCII metadata (RECOMMENDED)",
    "tIME": "Modification timestamp (RECOMMENDED)"
  }
}
        

• MUST include embedded ICC color profile (iCCP chunk)
• MUST include UTF-8 metadata in iTXt chunks
• SHOULD use 16-bit depth for professional/archival work
• MUST NOT use any lossy preprocessing

4.1.3 JPEG Requirements

JPEG remains essential for photographic content and web distribution. While lossy compression is inherent to the format, quality parameters ensure acceptable fidelity:

• Quality setting MUST be ≥85 for distribution
• MUST use 4:4:4 chroma sampling (no subsampling)
• MUST include EXIF 2.3+ metadata
• SHOULD use progressive encoding for web

4.1.4 Vector Graphics

For vector artwork, SVG (Scalable Vector Graphics) is the primary format:

<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns="http://www.w3.org/2000/svg"
     xmlns:wia="https://wia.org/standards/ART-001/v1"
     version="1.1"
     viewBox="0 0 1000 1000">
  <metadata>
    <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
             xmlns:dc="http://purl.org/dc/elements/1.1/">
      <rdf:Description rdf:about="">
        <dc:title>Artwork Title</dc:title>
        <dc:creator>Artist Name</dc:creator>
        <dc:rights>© 2025 Artist Name</dc:rights>
      </rdf:Description>
    </rdf:RDF>
  </metadata>
  <!-- Artwork content -->
</svg>
        

4.1.5 3D Assets

For three-dimensional digital art, glTF 2.0 is the standard format:

{
  "asset": {
    "version": "2.0",
    "generator": "WIA-ART-001 Exporter v1.0"
  },
  "extensionsUsed": [
    "KHR_materials_pbrSpecularGlossiness",
    "WIA_art_metadata"
  ],
  "extensions": {
    "WIA_art_metadata": {
      "title": "3D Sculpture",
      "artist": "Artist Name",
      "created": "2025-01-15T10:30:00Z",
      "license": "CC BY-SA 4.0"
    }
  }
}
        

4.2 Core Metadata Schema

The metadata schema defines how information about digital artwork is structured and stored. This comprehensive schema accommodates technical, descriptive, administrative, and preservation metadata.

4.2.1 Schema Structure

{
  "@context": "https://wia.org/standards/ART-001/v1",
  "@type": "DigitalArtwork",
  "id": "uuid:12345678-1234-1234-1234-123456789abc",
  "version": "1.0",
  "timestamp": "2025-01-15T10:30:00Z",
  
  "artwork": {
    "title": "Sunset Over Mountains",
    "subtitle": "Evening Light Series #3",
    "description": "A digital painting capturing...",
    "created": "2025-01-15T10:30:00Z",
    "modified": "2025-01-16T14:00:00Z"
  },
  
  "artist": {
    "name": "Jane Doe",
    "id": "did:wia:artist:jane-doe",
    "url": "https://artist.example.com",
    "nationality": "US"
  },
  
  "technical": {
    "medium": "digital-painting",
    "format": {
      "mimeType": "image/png",
      "extension": "png"
    },
    "dimensions": {
      "width": 4096,
      "height": 2160,
      "unit": "px",
      "dpi": 300
    },
    "color": {
      "space": "Adobe RGB",
      "profile": "Adobe RGB (1998)",
      "bitDepth": 16
    },
    "fileSize": 52428800,
    "checksum": {
      "algorithm": "SHA-256",
      "value": "a1b2c3d4..."
    }
  },
  
  "rights": {
    "copyright": "© 2025 Jane Doe",
    "license": {
      "type": "CC-BY-SA-4.0",
      "url": "https://creativecommons.org/licenses/by-sa/4.0/"
    }
  }
}
        

4.2.2 Required Fields

Table 4.2: Required Metadata Fields

Field	Type	Description
id	string	UUID v4 or URI identifier
artwork.title	string	1-200 characters
artist.name	string	Creator's name or pseudonym
technical.format.mimeType	string	IANA media type
technical.dimensions	object	Width, height, unit
rights.copyright	string	Copyright notice

4.2.3 Medium Enumeration

Valid values for the technical.medium field:

• digital-painting - Created with digital painting tools
• 3d-modeling - Three-dimensional computer graphics
• vector-art - Vector-based illustration
• pixel-art - Pixel-based art
• generative - Algorithmically generated
• photo-manipulation - Edited photography
• mixed-media - Combination of techniques
• ai-assisted - Created with AI tools

4.3 Color Space Requirements

Consistent color reproduction across devices requires proper color management. All WIA-compliant artwork MUST specify color space and embed appropriate ICC profiles.

Table 4.3: Standard Color Spaces

Color Space	Usage	Gamut	Profile
sRGB	Web, general use	Standard	IEC 61966-2-1
Adobe RGB	Professional print	Wide	Adobe RGB (1998)
Display P3	Modern displays	Wide	Display P3
ProPhoto RGB	Archival, editing	Ultra-wide	ROMM RGB

4.4 Quality Tiers

Different use cases require different quality levels. The standard defines three tiers:

4.4.1 Archival Master

• Format: TIFF or PNG (lossless)
• Bit Depth: 16-bit minimum
• Color Space: ProPhoto RGB or Adobe RGB
• Resolution: Maximum available
• Metadata: Complete

4.4.2 Professional Distribution

• Format: PNG or high-quality JPEG
• Bit Depth: 8-bit or 16-bit
• Color Space: Adobe RGB or sRGB
• DPI: 300 minimum

4.4.3 Web Display

• Format: WebP, AVIF, or JPEG
• Bit Depth: 8-bit
• Color Space: sRGB
• File Size: Optimized

4.5 File Naming Convention

{artist-slug}_{artwork-slug}_{version}_{variant}.{ext}

Examples:
jane-doe_sunset-mountains_v1_master.tiff
jane-doe_sunset-mountains_v1_web.jpg
jane-doe_sunset-mountains_v1_thumb.webp
        

4.6 Validation Requirements

All WIA-compliant files MUST pass these validation checks:

1. Valid file format structure
2. Embedded ICC color profile
3. Core metadata fields present
4. Checksum matches content
5. File size within acceptable limits
6. Proper UTF-8 encoding for text
7. Valid URI/URL references

4.7 Chapter Summary

4.8 Review Questions

4.9 Looking Ahead

Chapter 5 covers Phase 2: API Interface specification, detailing the REST API endpoints, TypeScript SDK, and authentication mechanisms that enable programmatic access to WIA-compliant artwork data.