Crate qrism 

qrism

A Rust library for generating and reading QR codes with Reed-Solomon error correction. Supports traditional monochromatic QR codes with additional experimental multicolor QR support for enhanced storage capacity.

Features

• QR Code Generation: Create QR codes with customizable versions, error correction levels, and capacity
• QR Code Reading: Detect and decode QR codes from images with robust error correction
• Reed-Solomon Error Correction: Built-in error correction with configurable levels (L, M, Q, H)
• High Capacity QR Support: Experimental polychromatic QR codes with 3x storage capacity
• Image Processing: Advanced binarization and geometric correction for reliable detection

Quick Start

Simple QR Code Generation

use qrism::QRBuilder;

// Simplest usage - provide only data, all other settings are automatically chosen
let qr = QRBuilder::new(b"Hello, World!")
    .build()?;

let img = qr.to_image(4);  // 4x scale factor
img.save("simple_qr.png")?;

Full Configuration

use qrism::{QRBuilder, ECLevel, Version, MaskPattern};

let data = "Hello, World!";
let qr = QRBuilder::new(data.as_bytes())
    .version(Version::Normal(2))  // QR version (size) - if not provided, finds smallest version to fit data
    .ec_level(ECLevel::M)         // Error correction level - if not provided, defaults to ECLevel::M
    .high_capacity(false)         // Standard capacity mode - if not provided, defaults to false
    .mask(MaskPattern::new(3))    // Mask pattern - if not provided, finds best mask based on penalty score
    .build()?;

let img = qr.to_image(4);  // 4x scale factor
img.save("configured_qr.png")?;

Reading a QR Code

use qrism::reader::detect_qr;

// Load and prepare image
let img = image::open("qr_code.png")?;

// Detect and decode QR codes
let mut res = detect_qr(&img);
if let Some(symbol) = res.symbols().first_mut() {
    let (metadata, message) = symbol.decode()?;
    println!("Decoded: {}", message);
}

Reading a high capacity multi color QR

use qrism::reader::detect_hc_qr;

// Load and prepare image
let img = image::open("qr_code.png")?;

// Detect and decode QR codes
let mut res = detect_hc_qr(&img);
if let Some(symbol) = res.symbols().first_mut() {
    let (metadata, message) = symbol.decode()?;
    println!("Decoded: {}", message);
}

QR Code Components

Versions

• Micro QR: Versions 1-4 for small data (experimental)
• Normal QR: Versions 1-40, with sizes from 21x21 to 177x177 modules

Error Correction Levels

• L (Low): ~7% error correction
• M (Medium): ~15% error correction
• Q (Quartile): ~25% error correction
• H (High): ~30% error correction

High Capacity QR Codes

High capacity QR codes are an extension of traditional QR codes that achieve 3x the storage capacity by leveraging color channels for data encoding. Unlike standard monochromatic QR codes that use only black and white modules, high capacity QR codes utilize the full RGB color spectrum.

How It Works

The technology works by multiplexing three separate QR codes into a single visual code by encoding one in each of the red, green and blue color channels. Each color channel carries its own independent QR code with full Reed-Solomon error correction. When decoded, the three separate data streams are combined to reconstruct the original data, effectively tripling the storage capacity compared to traditional QR codes.

Example Usage

use qrism::QRBuilder;

// Create a high capacity QR code with 3x storage
let large_data = "Large dataset that would not fit in a standard QR code...".repeat(10);
let qr = QRBuilder::new(large_data.as_bytes())
    .high_capacity(true)  // Enable high capacity mode
    .build()?;

let img = qr.to_image(4);
img.save("high_capacity_qr.png")?;

Re-exports

pub use builder::QRBuilder;

pub use reader::*;

Modules

builder

reader

Macros

debug_println

Structs

MaskPattern

Enums

ECLevel

Version