SPQR - Stacked Polychromatic QR Codes

🌐 Live Demo: spqr.codes

Enhanced multi-layer QR code generator with bigger, more scannable modules for the same data.

Overview

SPQR (Stacked Polychromatic QR) uses multiple colour channels to create QR codes with larger modules for the same amount of data, making them easier to scan from a distance or on small screens. The technology splits data across colour layers while maintaining standard QR code structure.

✨ Features

Web Application (Recommended)

📱 Browser-based: No installation required
🎨 3 QR Variants: Standard, BWRG (4-color), CMYRGB (8-color)
🎯 1.4-1.5× Bigger Modules: Same data, larger squares, easier scanning
🛡️ Advanced Error Correction: Standard, Hybrid, and Parity modes
🌈 Custom Colors: Brand colors, accessibility presets (Deuteranopia, Protanopia)
📷 Camera Scanning: Upload images or use your camera
💾 Download: Export as SVG or PNG
🧪 Automated Testing: 29 comprehensive tests ensure reliability

CLI and Node.js Library

Command-line tools for batch processing
Programmatic API for integration

🚀 Quick Start

Option 1: Use the Web App (Easiest)

Visit spqr.codes and start generating codes immediately!

Option 2: Local Development

# Clone the repository
git clone https://github.com/YOUR_USERNAME/SPQR.git
cd SPQR
# Install dependencies
npm install
# Build TypeScript
npm run build
# Start local server
npm run dev

Visit http://localhost:3017 in your browser.

📊 How It Works

SPQR creates multi-layer QR codes by encoding data across different colour channels:

BWRG (4-Color SPQR)

2 layers: Base (black/white) + Red layer
Colours: White, Black, Red, Green (green = overlap)
Benefit: 1.4× bigger modules for same data
Best for: High contrast needs, 2-layer data

CMYRGB (8-Color SPQR)

3 layers: Base + Red + Green (or Parity)
Colours: 8 total (White, Red, Green, Yellow, Black, Magenta, Cyan, Blue)
Benefit: 1.5× bigger modules for same data
Error Correction Modes:
- Standard: All layers EC 'L' (maximum capacity)
- Hybrid: Base EC 'M', others EC 'L' (balanced)
- Parity: 2 data layers + 1 parity layer (maximum reliability)

Adaptive Color Decoder

The decoder uses nearest-neighbour colour matching, so it works with:

✅ Default colours
✅ Custom brand colours
✅ Accessibility-safe palettes
✅ Any valid colour combination

🧪 Testing

Web Interface

Open the browser console at spqr.codes and run:

runAllTests()

All 29 tests should pass:

Standard QR (4 tests)
BWRG Default (4 tests)
BWRG Custom (2 tests)
CMYRGB Standard, Hybrid, Parity (12 tests)
CMYRGB Custom Colors (7 tests)

Decoder Testing

For decoder development and debugging, use the test page:

docs/test-upload.html

This provides:

Generate test QR codes
Upload and decode test
Real-time console output
Isolated testing environment

Node.js Tests

npm test

📈 Capacity Limits

The generator enforces practical limits for reliable decoding:

Type	Max Version	Max Modules	Approx. Capacity
BWRG	30	141×141	~3,600 bytes total
CMYRGB Standard	25	121×121	~2,800 bytes total
CMYRGB Hybrid	22	109×109	~1,900 bytes total
CMYRGB Parity	25	121×121	~2,000 bytes data

🌐 Deployment

See DEPLOYMENT.md for GitHub Pages setup instructions.

📚 Documentation

ADAPTIVE_COLOR_DECODER.md - How the decoder works
DECODER_CALIBRATION.md - Future enhancement plans
TEST_GUIDE.md - Testing instructions

🤝 Contributing

Contributions are welcome! Please ensure all tests pass before submitting a pull request.

📄 License

MIT License - see LICENSE file for details

SPQR - Stacked Polychromatic QR Codes

🌐 Live Demo: spqr.codes

Enhanced multi-layer QR code generator with bigger, more scannable modules for the same data.

Overview

SPQR (Stacked Polychromatic QR) uses multiple colour channels to create QR codes with larger modules for the same amount of data, making them easier to scan from a distance or on small screens. The technology splits data across colour layers while maintaining standard QR code structure.

✨ Features

Web Application (Recommended)

📱 Browser-based: No installation required
🎨 3 QR Variants: Standard, BWRG (4-color), CMYRGB (8-color)
🎯 1.4-1.5× Bigger Modules: Same data, larger squares, easier scanning
🛡️ Advanced Error Correction: Standard, Hybrid, and Parity modes
🌈 Custom Colors: Brand colors, accessibility presets (Deuteranopia, Protanopia)
📷 Camera Scanning: Upload images or use your camera
💾 Download: Export as SVG or PNG
🧪 Automated Testing: 29 comprehensive tests ensure reliability

CLI and Node.js Library

Command-line tools for batch processing
Programmatic API for integration

🚀 Quick Start

Option 1: Use the Web App (Easiest)

Visit spqr.codes and start generating codes immediately!

Option 2: Local Development

# Clone the repository
git clone https://github.com/YOUR_USERNAME/SPQR.git
cd SPQR
# Install dependencies
npm install
# Build TypeScript
npm run build
# Start local server
npm run dev

Visit http://localhost:3017 in your browser.

📊 How It Works

SPQR creates multi-layer QR codes by encoding data across different colour channels:

BWRG (4-Color SPQR)

2 layers: Base (black/white) + Red layer
Colours: White, Black, Red, Green (green = overlap)
Benefit: 1.4× bigger modules for same data
Best for: High contrast needs, 2-layer data

CMYRGB (8-Color SPQR)

3 layers: Base + Red + Green (or Parity)
Colours: 8 total (White, Red, Green, Yellow, Black, Magenta, Cyan, Blue)
Benefit: 1.5× bigger modules for same data
Error Correction Modes:
- Standard: All layers EC 'L' (maximum capacity)
- Hybrid: Base EC 'M', others EC 'L' (balanced)
- Parity: 2 data layers + 1 parity layer (maximum reliability)

Adaptive Color Decoder

The decoder uses nearest-neighbour colour matching, so it works with:

✅ Default colours
✅ Custom brand colours
✅ Accessibility-safe palettes
✅ Any valid colour combination

🧪 Testing

Web Interface

Open the browser console at spqr.codes and run:

runAllTests()

All 29 tests should pass:

Standard QR (4 tests)
BWRG Default (4 tests)
BWRG Custom (2 tests)
CMYRGB Standard, Hybrid, Parity (12 tests)
CMYRGB Custom Colors (7 tests)

Decoder Testing

For decoder development and debugging, use the test page:

docs/test-upload.html

This provides:

Generate test QR codes
Upload and decode test
Real-time console output
Isolated testing environment

Node.js Tests

npm test

📈 Capacity Limits

The generator enforces practical limits for reliable decoding:

Type	Max Version	Max Modules	Approx. Capacity
BWRG	30	141×141	~3,600 bytes total
CMYRGB Standard	25	121×121	~2,800 bytes total
CMYRGB Hybrid	22	109×109	~1,900 bytes total
CMYRGB Parity	25	121×121	~2,000 bytes data

🌐 Deployment

See DEPLOYMENT.md for GitHub Pages setup instructions.

📚 Documentation

ADAPTIVE_COLOR_DECODER.md - How the decoder works
DECODER_CALIBRATION.md - Future enhancement plans
TEST_GUIDE.md - Testing instructions

🤝 Contributing

Contributions are welcome! Please ensure all tests pass before submitting a pull request.

📄 License

MIT License - see LICENSE file for details

SPQR - Stacked Polychromatic QR Codes

🌐 Live Demo: spqr.codes

Enhanced multi-layer QR code generator with bigger, more scannable modules for the same data.

Overview

SPQR (Stacked Polychromatic QR) uses multiple colour channels to create QR codes with larger modules for the same amount of data, making them easier to scan from a distance or on small screens. The technology splits data across colour layers while maintaining standard QR code structure.

✨ Features

Web Application (Recommended)

📱 Browser-based: No installation required
🎨 3 QR Variants: Standard, BWRG (4-color), CMYRGB (8-color)
🎯 1.4-1.5× Bigger Modules: Same data, larger squares, easier scanning
🛡️ Advanced Error Correction: Standard, Hybrid, and Parity modes
🌈 Custom Colors: Brand colors, accessibility presets (Deuteranopia, Protanopia)
📷 Camera Scanning: Upload images or use your camera
💾 Download: Export as SVG or PNG
🧪 Automated Testing: 29 comprehensive tests ensure reliability

CLI and Node.js Library

Command-line tools for batch processing
Programmatic API for integration

🚀 Quick Start

Option 1: Use the Web App (Easiest)

Visit spqr.codes and start generating codes immediately!

Option 2: Local Development

# Clone the repository
git clone https://github.com/YOUR_USERNAME/SPQR.git
cd SPQR
# Install dependencies
npm install
# Build TypeScript
npm run build
# Start local server
npm run dev

Visit http://localhost:3017 in your browser.

📊 How It Works

SPQR creates multi-layer QR codes by encoding data across different colour channels:

BWRG (4-Color SPQR)

2 layers: Base (black/white) + Red layer
Colours: White, Black, Red, Green (green = overlap)
Benefit: 1.4× bigger modules for same data
Best for: High contrast needs, 2-layer data

CMYRGB (8-Color SPQR)

3 layers: Base + Red + Green (or Parity)
Colours: 8 total (White, Red, Green, Yellow, Black, Magenta, Cyan, Blue)
Benefit: 1.5× bigger modules for same data
Error Correction Modes:
- Standard: All layers EC 'L' (maximum capacity)
- Hybrid: Base EC 'M', others EC 'L' (balanced)
- Parity: 2 data layers + 1 parity layer (maximum reliability)

Adaptive Color Decoder

The decoder uses nearest-neighbour colour matching, so it works with:

✅ Default colours
✅ Custom brand colours
✅ Accessibility-safe palettes
✅ Any valid colour combination

🧪 Testing

Web Interface

Open the browser console at spqr.codes and run:

runAllTests()

All 29 tests should pass:

Standard QR (4 tests)
BWRG Default (4 tests)
BWRG Custom (2 tests)
CMYRGB Standard, Hybrid, Parity (12 tests)
CMYRGB Custom Colors (7 tests)

Decoder Testing

For decoder development and debugging, use the test page:

docs/test-upload.html

This provides:

Generate test QR codes
Upload and decode test
Real-time console output
Isolated testing environment

Node.js Tests

npm test

📈 Capacity Limits

The generator enforces practical limits for reliable decoding:

Type	Max Version	Max Modules	Approx. Capacity
BWRG	30	141×141	~3,600 bytes total
CMYRGB Standard	25	121×121	~2,800 bytes total
CMYRGB Hybrid	22	109×109	~1,900 bytes total
CMYRGB Parity	25	121×121	~2,000 bytes data

🌐 Deployment

See DEPLOYMENT.md for GitHub Pages setup instructions.

📚 Documentation

ADAPTIVE_COLOR_DECODER.md - How the decoder works
DECODER_CALIBRATION.md - Future enhancement plans
TEST_GUIDE.md - Testing instructions

🤝 Contributing

Contributions are welcome! Please ensure all tests pass before submitting a pull request.

📄 License

MIT License - see LICENSE file for details

SPQR - Stacked Polychromatic QR Codes

🌐 Live Demo: spqr.codes

Enhanced multi-layer QR code generator with bigger, more scannable modules for the same data.

Overview

SPQR (Stacked Polychromatic QR) uses multiple colour channels to create QR codes with larger modules for the same amount of data, making them easier to scan from a distance or on small screens. The technology splits data across colour layers while maintaining standard QR code structure.

✨ Features

Web Application (Recommended)

📱 Browser-based: No installation required
🎨 3 QR Variants: Standard, BWRG (4-color), CMYRGB (8-color)
🎯 1.4-1.5× Bigger Modules: Same data, larger squares, easier scanning
🛡️ Advanced Error Correction: Standard, Hybrid, and Parity modes
🌈 Custom Colors: Brand colors, accessibility presets (Deuteranopia, Protanopia)
📷 Camera Scanning: Upload images or use your camera
💾 Download: Export as SVG or PNG
🧪 Automated Testing: 29 comprehensive tests ensure reliability

CLI and Node.js Library

Command-line tools for batch processing
Programmatic API for integration

🚀 Quick Start

Option 1: Use the Web App (Easiest)

Visit spqr.codes and start generating codes immediately!

Option 2: Local Development

# Clone the repository
git clone https://github.com/YOUR_USERNAME/SPQR.git
cd SPQR
# Install dependencies
npm install
# Build TypeScript
npm run build
# Start local server
npm run dev

Visit http://localhost:3017 in your browser.

📊 How It Works

SPQR creates multi-layer QR codes by encoding data across different colour channels:

BWRG (4-Color SPQR)

2 layers: Base (black/white) + Red layer
Colours: White, Black, Red, Green (green = overlap)
Benefit: 1.4× bigger modules for same data
Best for: High contrast needs, 2-layer data

CMYRGB (8-Color SPQR)

3 layers: Base + Red + Green (or Parity)
Colours: 8 total (White, Red, Green, Yellow, Black, Magenta, Cyan, Blue)
Benefit: 1.5× bigger modules for same data
Error Correction Modes:
- Standard: All layers EC 'L' (maximum capacity)
- Hybrid: Base EC 'M', others EC 'L' (balanced)
- Parity: 2 data layers + 1 parity layer (maximum reliability)

Adaptive Color Decoder

The decoder uses nearest-neighbour colour matching, so it works with:

✅ Default colours
✅ Custom brand colours
✅ Accessibility-safe palettes
✅ Any valid colour combination

🧪 Testing

Web Interface

Open the browser console at spqr.codes and run:

runAllTests()

All 29 tests should pass:

Standard QR (4 tests)
BWRG Default (4 tests)
BWRG Custom (2 tests)
CMYRGB Standard, Hybrid, Parity (12 tests)
CMYRGB Custom Colors (7 tests)

Decoder Testing

For decoder development and debugging, use the test page:

docs/test-upload.html

This provides:

Generate test QR codes
Upload and decode test
Real-time console output
Isolated testing environment

Node.js Tests

npm test

📈 Capacity Limits

The generator enforces practical limits for reliable decoding:

Type	Max Version	Max Modules	Approx. Capacity
BWRG	30	141×141	~3,600 bytes total
CMYRGB Standard	25	121×121	~2,800 bytes total
CMYRGB Hybrid	22	109×109	~1,900 bytes total
CMYRGB Parity	25	121×121	~2,000 bytes data

🌐 Deployment

See DEPLOYMENT.md for GitHub Pages setup instructions.

📚 Documentation

ADAPTIVE_COLOR_DECODER.md - How the decoder works
DECODER_CALIBRATION.md - Future enhancement plans
TEST_GUIDE.md - Testing instructions

🤝 Contributing

Contributions are welcome! Please ensure all tests pass before submitting a pull request.

📄 License

MIT License - see LICENSE file for details

SPQR - Stacked Polychromatic QR Codes

🌐 Live Demo: spqr.codes

Enhanced multi-layer QR code generator with bigger, more scannable modules for the same data.

Overview

SPQR (Stacked Polychromatic QR) uses multiple colour channels to create QR codes with larger modules for the same amount of data, making them easier to scan from a distance or on small screens. The technology splits data across colour layers while maintaining standard QR code structure.

✨ Features

Web Application (Recommended)

📱 Browser-based: No installation required
🎨 3 QR Variants: Standard, BWRG (4-color), CMYRGB (8-color)
🎯 1.4-1.5× Bigger Modules: Same data, larger squares, easier scanning
🛡️ Advanced Error Correction: Standard, Hybrid, and Parity modes
🌈 Custom Colors: Brand colors, accessibility presets (Deuteranopia, Protanopia)
📷 Camera Scanning: Upload images or use your camera
💾 Download: Export as SVG or PNG
🧪 Automated Testing: 29 comprehensive tests ensure reliability

CLI and Node.js Library

Command-line tools for batch processing
Programmatic API for integration

🚀 Quick Start

Option 1: Use the Web App (Easiest)

Visit spqr.codes and start generating codes immediately!

Option 2: Local Development

# Clone the repository
git clone https://github.com/YOUR_USERNAME/SPQR.git
cd SPQR
# Install dependencies
npm install
# Build TypeScript
npm run build
# Start local server
npm run dev

Visit http://localhost:3017 in your browser.

📊 How It Works

SPQR creates multi-layer QR codes by encoding data across different colour channels:

BWRG (4-Color SPQR)

2 layers: Base (black/white) + Red layer
Colours: White, Black, Red, Green (green = overlap)
Benefit: 1.4× bigger modules for same data
Best for: High contrast needs, 2-layer data

CMYRGB (8-Color SPQR)

3 layers: Base + Red + Green (or Parity)
Colours: 8 total (White, Red, Green, Yellow, Black, Magenta, Cyan, Blue)
Benefit: 1.5× bigger modules for same data
Error Correction Modes:
- Standard: All layers EC 'L' (maximum capacity)
- Hybrid: Base EC 'M', others EC 'L' (balanced)
- Parity: 2 data layers + 1 parity layer (maximum reliability)

Adaptive Color Decoder

The decoder uses nearest-neighbour colour matching, so it works with:

✅ Default colours
✅ Custom brand colours
✅ Accessibility-safe palettes
✅ Any valid colour combination

🧪 Testing

Web Interface

Open the browser console at spqr.codes and run:

runAllTests()

All 29 tests should pass:

Standard QR (4 tests)
BWRG Default (4 tests)
BWRG Custom (2 tests)
CMYRGB Standard, Hybrid, Parity (12 tests)
CMYRGB Custom Colors (7 tests)

Decoder Testing

For decoder development and debugging, use the test page:

docs/test-upload.html

This provides:

Generate test QR codes
Upload and decode test
Real-time console output
Isolated testing environment

Node.js Tests

npm test

📈 Capacity Limits

The generator enforces practical limits for reliable decoding:

Type	Max Version	Max Modules	Approx. Capacity
BWRG	30	141×141	~3,600 bytes total
CMYRGB Standard	25	121×121	~2,800 bytes total
CMYRGB Hybrid	22	109×109	~1,900 bytes total
CMYRGB Parity	25	121×121	~2,000 bytes data

🌐 Deployment

See DEPLOYMENT.md for GitHub Pages setup instructions.

📚 Documentation

ADAPTIVE_COLOR_DECODER.md - How the decoder works
DECODER_CALIBRATION.md - Future enhancement plans
TEST_GUIDE.md - Testing instructions

🤝 Contributing

Contributions are welcome! Please ensure all tests pass before submitting a pull request.

📄 License

MIT License - see LICENSE file for details

SPQR - Stacked Polychromatic QR Codes

🌐 Live Demo: spqr.codes

Enhanced multi-layer QR code generator with bigger, more scannable modules for the same data.

Overview

SPQR (Stacked Polychromatic QR) uses multiple colour channels to create QR codes with larger modules for the same amount of data, making them easier to scan from a distance or on small screens. The technology splits data across colour layers while maintaining standard QR code structure.

✨ Features

Web Application (Recommended)

📱 Browser-based: No installation required
🎨 3 QR Variants: Standard, BWRG (4-color), CMYRGB (8-color)
🎯 1.4-1.5× Bigger Modules: Same data, larger squares, easier scanning
🛡️ Advanced Error Correction: Standard, Hybrid, and Parity modes
🌈 Custom Colors: Brand colors, accessibility presets (Deuteranopia, Protanopia)
📷 Camera Scanning: Upload images or use your camera
💾 Download: Export as SVG or PNG
🧪 Automated Testing: 29 comprehensive tests ensure reliability

CLI and Node.js Library

Command-line tools for batch processing
Programmatic API for integration

🚀 Quick Start

Option 1: Use the Web App (Easiest)

Visit spqr.codes and start generating codes immediately!

Option 2: Local Development

# Clone the repository
git clone https://github.com/YOUR_USERNAME/SPQR.git
cd SPQR
# Install dependencies
npm install
# Build TypeScript
npm run build
# Start local server
npm run dev

Visit http://localhost:3017 in your browser.

📊 How It Works

SPQR creates multi-layer QR codes by encoding data across different colour channels:

BWRG (4-Color SPQR)

2 layers: Base (black/white) + Red layer
Colours: White, Black, Red, Green (green = overlap)
Benefit: 1.4× bigger modules for same data
Best for: High contrast needs, 2-layer data

CMYRGB (8-Color SPQR)

3 layers: Base + Red + Green (or Parity)
Colours: 8 total (White, Red, Green, Yellow, Black, Magenta, Cyan, Blue)
Benefit: 1.5× bigger modules for same data
Error Correction Modes:
- Standard: All layers EC 'L' (maximum capacity)
- Hybrid: Base EC 'M', others EC 'L' (balanced)
- Parity: 2 data layers + 1 parity layer (maximum reliability)

Adaptive Color Decoder

The decoder uses nearest-neighbour colour matching, so it works with:

✅ Default colours
✅ Custom brand colours
✅ Accessibility-safe palettes
✅ Any valid colour combination

🧪 Testing

Web Interface

Open the browser console at spqr.codes and run:

runAllTests()

All 29 tests should pass:

Standard QR (4 tests)
BWRG Default (4 tests)
BWRG Custom (2 tests)
CMYRGB Standard, Hybrid, Parity (12 tests)
CMYRGB Custom Colors (7 tests)

Decoder Testing

For decoder development and debugging, use the test page:

docs/test-upload.html

This provides:

Generate test QR codes
Upload and decode test
Real-time console output
Isolated testing environment

Node.js Tests

npm test

📈 Capacity Limits

The generator enforces practical limits for reliable decoding:

Type	Max Version	Max Modules	Approx. Capacity
BWRG	30	141×141	~3,600 bytes total
CMYRGB Standard	25	121×121	~2,800 bytes total
CMYRGB Hybrid	22	109×109	~1,900 bytes total
CMYRGB Parity	25	121×121	~2,000 bytes data

🌐 Deployment

See DEPLOYMENT.md for GitHub Pages setup instructions.

📚 Documentation

ADAPTIVE_COLOR_DECODER.md - How the decoder works
DECODER_CALIBRATION.md - Future enhancement plans
TEST_GUIDE.md - Testing instructions

🤝 Contributing

Contributions are welcome! Please ensure all tests pass before submitting a pull request.

📄 License

MIT License - see LICENSE file for details

SPQR - Stacked Polychromatic QR Codes

🌐 Live Demo: spqr.codes

Enhanced multi-layer QR code generator with bigger, more scannable modules for the same data.

Overview

SPQR (Stacked Polychromatic QR) uses multiple colour channels to create QR codes with larger modules for the same amount of data, making them easier to scan from a distance or on small screens. The technology splits data across colour layers while maintaining standard QR code structure.

✨ Features

Web Application (Recommended)

📱 Browser-based: No installation required
🎨 3 QR Variants: Standard, BWRG (4-color), CMYRGB (8-color)
🎯 1.4-1.5× Bigger Modules: Same data, larger squares, easier scanning
🛡️ Advanced Error Correction: Standard, Hybrid, and Parity modes
🌈 Custom Colors: Brand colors, accessibility presets (Deuteranopia, Protanopia)
📷 Camera Scanning: Upload images or use your camera
💾 Download: Export as SVG or PNG
🧪 Automated Testing: 29 comprehensive tests ensure reliability

CLI and Node.js Library

Command-line tools for batch processing
Programmatic API for integration

🚀 Quick Start

Option 1: Use the Web App (Easiest)

Visit spqr.codes and start generating codes immediately!

Option 2: Local Development

# Clone the repository
git clone https://github.com/YOUR_USERNAME/SPQR.git
cd SPQR
# Install dependencies
npm install
# Build TypeScript
npm run build
# Start local server
npm run dev

Visit http://localhost:3017 in your browser.

📊 How It Works

SPQR creates multi-layer QR codes by encoding data across different colour channels:

BWRG (4-Color SPQR)

2 layers: Base (black/white) + Red layer
Colours: White, Black, Red, Green (green = overlap)
Benefit: 1.4× bigger modules for same data
Best for: High contrast needs, 2-layer data

CMYRGB (8-Color SPQR)

3 layers: Base + Red + Green (or Parity)
Colours: 8 total (White, Red, Green, Yellow, Black, Magenta, Cyan, Blue)
Benefit: 1.5× bigger modules for same data
Error Correction Modes:
- Standard: All layers EC 'L' (maximum capacity)
- Hybrid: Base EC 'M', others EC 'L' (balanced)
- Parity: 2 data layers + 1 parity layer (maximum reliability)

Adaptive Color Decoder

The decoder uses nearest-neighbour colour matching, so it works with:

✅ Default colours
✅ Custom brand colours
✅ Accessibility-safe palettes
✅ Any valid colour combination

🧪 Testing

Web Interface

Open the browser console at spqr.codes and run:

runAllTests()

All 29 tests should pass:

Standard QR (4 tests)
BWRG Default (4 tests)
BWRG Custom (2 tests)
CMYRGB Standard, Hybrid, Parity (12 tests)
CMYRGB Custom Colors (7 tests)

Decoder Testing

For decoder development and debugging, use the test page:

docs/test-upload.html

This provides:

Generate test QR codes
Upload and decode test
Real-time console output
Isolated testing environment

Node.js Tests

npm test

📈 Capacity Limits

The generator enforces practical limits for reliable decoding:

Type	Max Version	Max Modules	Approx. Capacity
BWRG	30	141×141	~3,600 bytes total
CMYRGB Standard	25	121×121	~2,800 bytes total
CMYRGB Hybrid	22	109×109	~1,900 bytes total
CMYRGB Parity	25	121×121	~2,000 bytes data

🌐 Deployment

See DEPLOYMENT.md for GitHub Pages setup instructions.

📚 Documentation

ADAPTIVE_COLOR_DECODER.md - How the decoder works
DECODER_CALIBRATION.md - Future enhancement plans
TEST_GUIDE.md - Testing instructions

🤝 Contributing

Contributions are welcome! Please ensure all tests pass before submitting a pull request.

📄 License

MIT License - see LICENSE file for details

SPQR - Stacked Polychromatic QR Codes

🌐 Live Demo: spqr.codes

Enhanced multi-layer QR code generator with bigger, more scannable modules for the same data.

Overview

SPQR (Stacked Polychromatic QR) uses multiple colour channels to create QR codes with larger modules for the same amount of data, making them easier to scan from a distance or on small screens. The technology splits data across colour layers while maintaining standard QR code structure.

✨ Features

Web Application (Recommended)

📱 Browser-based: No installation required
🎨 3 QR Variants: Standard, BWRG (4-color), CMYRGB (8-color)
🎯 1.4-1.5× Bigger Modules: Same data, larger squares, easier scanning
🛡️ Advanced Error Correction: Standard, Hybrid, and Parity modes
🌈 Custom Colors: Brand colors, accessibility presets (Deuteranopia, Protanopia)
📷 Camera Scanning: Upload images or use your camera
💾 Download: Export as SVG or PNG
🧪 Automated Testing: 29 comprehensive tests ensure reliability

CLI and Node.js Library

Command-line tools for batch processing
Programmatic API for integration

🚀 Quick Start

Option 1: Use the Web App (Easiest)

Visit spqr.codes and start generating codes immediately!

Option 2: Local Development

# Clone the repository
git clone https://github.com/YOUR_USERNAME/SPQR.git
cd SPQR
# Install dependencies
npm install
# Build TypeScript
npm run build
# Start local server
npm run dev

Visit http://localhost:3017 in your browser.

📊 How It Works

SPQR creates multi-layer QR codes by encoding data across different colour channels:

BWRG (4-Color SPQR)

2 layers: Base (black/white) + Red layer
Colours: White, Black, Red, Green (green = overlap)
Benefit: 1.4× bigger modules for same data
Best for: High contrast needs, 2-layer data

CMYRGB (8-Color SPQR)

3 layers: Base + Red + Green (or Parity)
Colours: 8 total (White, Red, Green, Yellow, Black, Magenta, Cyan, Blue)
Benefit: 1.5× bigger modules for same data
Error Correction Modes:
- Standard: All layers EC 'L' (maximum capacity)
- Hybrid: Base EC 'M', others EC 'L' (balanced)
- Parity: 2 data layers + 1 parity layer (maximum reliability)

Adaptive Color Decoder

The decoder uses nearest-neighbour colour matching, so it works with:

✅ Default colours
✅ Custom brand colours
✅ Accessibility-safe palettes
✅ Any valid colour combination

🧪 Testing

Web Interface

Open the browser console at spqr.codes and run:

runAllTests()

All 29 tests should pass:

Standard QR (4 tests)
BWRG Default (4 tests)
BWRG Custom (2 tests)
CMYRGB Standard, Hybrid, Parity (12 tests)
CMYRGB Custom Colors (7 tests)

Decoder Testing

For decoder development and debugging, use the test page:

docs/test-upload.html

This provides:

Generate test QR codes
Upload and decode test
Real-time console output
Isolated testing environment

Node.js Tests

npm test

📈 Capacity Limits

The generator enforces practical limits for reliable decoding:

Type	Max Version	Max Modules	Approx. Capacity
BWRG	30	141×141	~3,600 bytes total
CMYRGB Standard	25	121×121	~2,800 bytes total
CMYRGB Hybrid	22	109×109	~1,900 bytes total
CMYRGB Parity	25	121×121	~2,000 bytes data

🌐 Deployment

See DEPLOYMENT.md for GitHub Pages setup instructions.

📚 Documentation

ADAPTIVE_COLOR_DECODER.md - How the decoder works
DECODER_CALIBRATION.md - Future enhancement plans
TEST_GUIDE.md - Testing instructions

🤝 Contributing

Contributions are welcome! Please ensure all tests pass before submitting a pull request.

📄 License

MIT License - see LICENSE file for details

Name		Name	Last commit message	Last commit date
dist		dist
docs		docs
src		src
test		test
.gitignore		.gitignore
ADAPTIVE_COLOR_DECODER.md		ADAPTIVE_COLOR_DECODER.md
AGGREGATOR_FIXES_20251103.md		AGGREGATOR_FIXES_20251103.md
BWRG_AND_GRID_20251103.md		BWRG_AND_GRID_20251103.md
CAMERA_IMPROVEMENTS_20251103.md		CAMERA_IMPROVEMENTS_20251103.md
CANVAS_FIX_20251103i.md		CANVAS_FIX_20251103i.md
CHANGES_20251028.md		CHANGES_20251028.md
CNAME		CNAME
CORNER_MARKERS_20251103.md		CORNER_MARKERS_20251103.md
CRITICAL_FIX_20251028c.md		CRITICAL_FIX_20251028c.md
CRITICAL_FIX_20251028d.md		CRITICAL_FIX_20251028d.md
CURRENT_STATUS.md		CURRENT_STATUS.md
DECODER_CALIBRATION.md		DECODER_CALIBRATION.md
DECODER_FIXES_SUMMARY.md		DECODER_FIXES_SUMMARY.md
DEPLOYMENT.md		DEPLOYMENT.md
DEPLOY_CHECKLIST.md		DEPLOY_CHECKLIST.md
ERROR_CORRECTION_MODES.md		ERROR_CORRECTION_MODES.md
FIXES_20251103.md		FIXES_20251103.md
LICENSE		LICENSE
OVERLAY_AND_FINDER_20251103.md		OVERLAY_AND_FINDER_20251103.md
PUBLIC_RELEASE_NOTES.md		PUBLIC_RELEASE_NOTES.md
README.md		README.md
RELEASE_NOTES.md		RELEASE_NOTES.md
SESSION_SUMMARY.md		SESSION_SUMMARY.md
SPEC.md		SPEC.md
TEST_GUIDE.md		TEST_GUIDE.md
VERIFICATION_20251103.md		VERIFICATION_20251103.md
capacity_results.json		capacity_results.json
comprehensive_test.js		comprehensive_test.js
debug_base.png		debug_base.png
debug_decoder.js		debug_decoder.js
debug_qr.svg		debug_qr.svg
debug_qr_decoder.js		debug_qr_decoder.js
debug_red.png		debug_red.png
eslint.config.js		eslint.config.js
package.json		package.json
spqr@1.1.0		spqr@1.1.0
test_3layer.png		test_3layer.png
test_all_decoders.sh		test_all_decoders.sh
test_browser_decoder.html		test_browser_decoder.html
test_complex.svg		test_complex.svg
test_qr.svg		test_qr.svg
test_roundtrip.js		test_roundtrip.js
test_spqr_decoder.sh		test_spqr_decoder.sh
tsconfig.json		tsconfig.json
tsx		tsx

Name		Name	Last commit message	Last commit date
dist		dist
docs		docs
src		src
test		test
.gitignore		.gitignore
ADAPTIVE_COLOR_DECODER.md		ADAPTIVE_COLOR_DECODER.md
AGGREGATOR_FIXES_20251103.md		AGGREGATOR_FIXES_20251103.md
BWRG_AND_GRID_20251103.md		BWRG_AND_GRID_20251103.md
CAMERA_IMPROVEMENTS_20251103.md		CAMERA_IMPROVEMENTS_20251103.md
CANVAS_FIX_20251103i.md		CANVAS_FIX_20251103i.md
CHANGES_20251028.md		CHANGES_20251028.md
CNAME		CNAME
CORNER_MARKERS_20251103.md		CORNER_MARKERS_20251103.md
CRITICAL_FIX_20251028c.md		CRITICAL_FIX_20251028c.md
CRITICAL_FIX_20251028d.md		CRITICAL_FIX_20251028d.md
CURRENT_STATUS.md		CURRENT_STATUS.md
DECODER_CALIBRATION.md		DECODER_CALIBRATION.md
DECODER_FIXES_SUMMARY.md		DECODER_FIXES_SUMMARY.md
DEPLOYMENT.md		DEPLOYMENT.md
DEPLOY_CHECKLIST.md		DEPLOY_CHECKLIST.md
ERROR_CORRECTION_MODES.md		ERROR_CORRECTION_MODES.md
FIXES_20251103.md		FIXES_20251103.md
LICENSE		LICENSE
OVERLAY_AND_FINDER_20251103.md		OVERLAY_AND_FINDER_20251103.md
PUBLIC_RELEASE_NOTES.md		PUBLIC_RELEASE_NOTES.md
README.md		README.md
RELEASE_NOTES.md		RELEASE_NOTES.md
SESSION_SUMMARY.md		SESSION_SUMMARY.md
SPEC.md		SPEC.md
TEST_GUIDE.md		TEST_GUIDE.md
VERIFICATION_20251103.md		VERIFICATION_20251103.md
capacity_results.json		capacity_results.json
comprehensive_test.js		comprehensive_test.js
debug_base.png		debug_base.png
debug_decoder.js		debug_decoder.js
debug_qr.svg		debug_qr.svg
debug_qr_decoder.js		debug_qr_decoder.js
debug_red.png		debug_red.png
eslint.config.js		eslint.config.js
package.json		package.json
spqr@1.1.0		spqr@1.1.0
test_3layer.png		test_3layer.png
test_all_decoders.sh		test_all_decoders.sh
test_browser_decoder.html		test_browser_decoder.html
test_complex.svg		test_complex.svg
test_qr.svg		test_qr.svg
test_roundtrip.js		test_roundtrip.js
test_spqr_decoder.sh		test_spqr_decoder.sh
tsconfig.json		tsconfig.json
tsx		tsx

Name		Name	Last commit message	Last commit date
dist		dist
docs		docs
src		src
test		test
.gitignore		.gitignore
ADAPTIVE_COLOR_DECODER.md		ADAPTIVE_COLOR_DECODER.md
AGGREGATOR_FIXES_20251103.md		AGGREGATOR_FIXES_20251103.md
BWRG_AND_GRID_20251103.md		BWRG_AND_GRID_20251103.md
CAMERA_IMPROVEMENTS_20251103.md		CAMERA_IMPROVEMENTS_20251103.md
CANVAS_FIX_20251103i.md		CANVAS_FIX_20251103i.md
CHANGES_20251028.md		CHANGES_20251028.md
CNAME		CNAME
CORNER_MARKERS_20251103.md		CORNER_MARKERS_20251103.md
CRITICAL_FIX_20251028c.md		CRITICAL_FIX_20251028c.md
CRITICAL_FIX_20251028d.md		CRITICAL_FIX_20251028d.md
CURRENT_STATUS.md		CURRENT_STATUS.md
DECODER_CALIBRATION.md		DECODER_CALIBRATION.md
DECODER_FIXES_SUMMARY.md		DECODER_FIXES_SUMMARY.md
DEPLOYMENT.md		DEPLOYMENT.md
DEPLOY_CHECKLIST.md		DEPLOY_CHECKLIST.md
ERROR_CORRECTION_MODES.md		ERROR_CORRECTION_MODES.md
FIXES_20251103.md		FIXES_20251103.md
LICENSE		LICENSE
OVERLAY_AND_FINDER_20251103.md		OVERLAY_AND_FINDER_20251103.md
PUBLIC_RELEASE_NOTES.md		PUBLIC_RELEASE_NOTES.md
README.md		README.md
RELEASE_NOTES.md		RELEASE_NOTES.md
SESSION_SUMMARY.md		SESSION_SUMMARY.md
SPEC.md		SPEC.md
TEST_GUIDE.md		TEST_GUIDE.md
VERIFICATION_20251103.md		VERIFICATION_20251103.md
capacity_results.json		capacity_results.json
comprehensive_test.js		comprehensive_test.js
debug_base.png		debug_base.png
debug_decoder.js		debug_decoder.js
debug_qr.svg		debug_qr.svg
debug_qr_decoder.js		debug_qr_decoder.js
debug_red.png		debug_red.png
eslint.config.js		eslint.config.js
package.json		package.json
spqr@1.1.0		spqr@1.1.0
test_3layer.png		test_3layer.png
test_all_decoders.sh		test_all_decoders.sh
test_browser_decoder.html		test_browser_decoder.html
test_complex.svg		test_complex.svg
test_qr.svg		test_qr.svg
test_roundtrip.js		test_roundtrip.js
test_spqr_decoder.sh		test_spqr_decoder.sh
tsconfig.json		tsconfig.json
tsx		tsx

Name		Name	Last commit message	Last commit date
dist		dist
docs		docs
src		src
test		test
.gitignore		.gitignore
ADAPTIVE_COLOR_DECODER.md		ADAPTIVE_COLOR_DECODER.md
AGGREGATOR_FIXES_20251103.md		AGGREGATOR_FIXES_20251103.md
BWRG_AND_GRID_20251103.md		BWRG_AND_GRID_20251103.md
CAMERA_IMPROVEMENTS_20251103.md		CAMERA_IMPROVEMENTS_20251103.md
CANVAS_FIX_20251103i.md		CANVAS_FIX_20251103i.md
CHANGES_20251028.md		CHANGES_20251028.md
CNAME		CNAME
CORNER_MARKERS_20251103.md		CORNER_MARKERS_20251103.md
CRITICAL_FIX_20251028c.md		CRITICAL_FIX_20251028c.md
CRITICAL_FIX_20251028d.md		CRITICAL_FIX_20251028d.md
CURRENT_STATUS.md		CURRENT_STATUS.md
DECODER_CALIBRATION.md		DECODER_CALIBRATION.md
DECODER_FIXES_SUMMARY.md		DECODER_FIXES_SUMMARY.md
DEPLOYMENT.md		DEPLOYMENT.md
DEPLOY_CHECKLIST.md		DEPLOY_CHECKLIST.md
ERROR_CORRECTION_MODES.md		ERROR_CORRECTION_MODES.md
FIXES_20251103.md		FIXES_20251103.md
LICENSE		LICENSE
OVERLAY_AND_FINDER_20251103.md		OVERLAY_AND_FINDER_20251103.md
PUBLIC_RELEASE_NOTES.md		PUBLIC_RELEASE_NOTES.md
README.md		README.md
RELEASE_NOTES.md		RELEASE_NOTES.md
SESSION_SUMMARY.md		SESSION_SUMMARY.md
SPEC.md		SPEC.md
TEST_GUIDE.md		TEST_GUIDE.md
VERIFICATION_20251103.md		VERIFICATION_20251103.md
capacity_results.json		capacity_results.json
comprehensive_test.js		comprehensive_test.js
debug_base.png		debug_base.png
debug_decoder.js		debug_decoder.js
debug_qr.svg		debug_qr.svg
debug_qr_decoder.js		debug_qr_decoder.js
debug_red.png		debug_red.png
eslint.config.js		eslint.config.js
package.json		package.json
spqr@1.1.0		spqr@1.1.0
test_3layer.png		test_3layer.png
test_all_decoders.sh		test_all_decoders.sh
test_browser_decoder.html		test_browser_decoder.html
test_complex.svg		test_complex.svg
test_qr.svg		test_qr.svg
test_roundtrip.js		test_roundtrip.js
test_spqr_decoder.sh		test_spqr_decoder.sh
tsconfig.json		tsconfig.json
tsx		tsx

Name		Name	Last commit message	Last commit date
dist		dist
docs		docs
src		src
test		test
.gitignore		.gitignore
ADAPTIVE_COLOR_DECODER.md		ADAPTIVE_COLOR_DECODER.md
AGGREGATOR_FIXES_20251103.md		AGGREGATOR_FIXES_20251103.md
BWRG_AND_GRID_20251103.md		BWRG_AND_GRID_20251103.md
CAMERA_IMPROVEMENTS_20251103.md		CAMERA_IMPROVEMENTS_20251103.md
CANVAS_FIX_20251103i.md		CANVAS_FIX_20251103i.md
CHANGES_20251028.md		CHANGES_20251028.md
CNAME		CNAME
CORNER_MARKERS_20251103.md		CORNER_MARKERS_20251103.md
CRITICAL_FIX_20251028c.md		CRITICAL_FIX_20251028c.md
CRITICAL_FIX_20251028d.md		CRITICAL_FIX_20251028d.md
CURRENT_STATUS.md		CURRENT_STATUS.md
DECODER_CALIBRATION.md		DECODER_CALIBRATION.md
DECODER_FIXES_SUMMARY.md		DECODER_FIXES_SUMMARY.md
DEPLOYMENT.md		DEPLOYMENT.md
DEPLOY_CHECKLIST.md		DEPLOY_CHECKLIST.md
ERROR_CORRECTION_MODES.md		ERROR_CORRECTION_MODES.md
FIXES_20251103.md		FIXES_20251103.md
LICENSE		LICENSE
OVERLAY_AND_FINDER_20251103.md		OVERLAY_AND_FINDER_20251103.md
PUBLIC_RELEASE_NOTES.md		PUBLIC_RELEASE_NOTES.md
README.md		README.md
RELEASE_NOTES.md		RELEASE_NOTES.md
SESSION_SUMMARY.md		SESSION_SUMMARY.md
SPEC.md		SPEC.md
TEST_GUIDE.md		TEST_GUIDE.md
VERIFICATION_20251103.md		VERIFICATION_20251103.md
capacity_results.json		capacity_results.json
comprehensive_test.js		comprehensive_test.js
debug_base.png		debug_base.png
debug_decoder.js		debug_decoder.js
debug_qr.svg		debug_qr.svg
debug_qr_decoder.js		debug_qr_decoder.js
debug_red.png		debug_red.png
eslint.config.js		eslint.config.js
package.json		package.json
spqr@1.1.0		spqr@1.1.0
test_3layer.png		test_3layer.png
test_all_decoders.sh		test_all_decoders.sh
test_browser_decoder.html		test_browser_decoder.html
test_complex.svg		test_complex.svg
test_qr.svg		test_qr.svg
test_roundtrip.js		test_roundtrip.js
test_spqr_decoder.sh		test_spqr_decoder.sh
tsconfig.json		tsconfig.json
tsx		tsx

Latest commit

History

Folders and files

Repository files navigation

SPQR - Stacked Polychromatic QR Codes

Overview

✨ Features

Web Application (Recommended)

CLI and Node.js Library

🚀 Quick Start

Option 1: Use the Web App (Easiest)

Option 2: Local Development

📊 How It Works

BWRG (4-Color SPQR)

CMYRGB (8-Color SPQR)

Adaptive Color Decoder

🧪 Testing

Web Interface

Decoder Testing

Node.js Tests

📈 Capacity Limits

🌐 Deployment

📚 Documentation

🤝 Contributing

📄 License

About

Resources

Stars

Watchers

Forks

Releases

Packages

Contributors

Languages

Latest commit

History

Folders and files

Repository files navigation

SPQR - Stacked Polychromatic QR Codes

Overview

✨ Features

Web Application (Recommended)

CLI and Node.js Library

🚀 Quick Start

Option 1: Use the Web App (Easiest)

Option 2: Local Development

📊 How It Works

BWRG (4-Color SPQR)

CMYRGB (8-Color SPQR)

Adaptive Color Decoder

🧪 Testing

Web Interface

Decoder Testing

Node.js Tests

📈 Capacity Limits

🌐 Deployment

📚 Documentation

🤝 Contributing

📄 License

About

Resources

Stars

Watchers

Forks

Releases

Packages

Contributors

Languages

Latest commit

History

Folders and files

Repository files navigation

SPQR - Stacked Polychromatic QR Codes

Overview

✨ Features

Web Application (Recommended)

CLI and Node.js Library

🚀 Quick Start

Option 1: Use the Web App (Easiest)

Option 2: Local Development