QR Code (Quick Response Code)

A QR code matrix is partitioned into Functional Patterns (for optical alignment) and Encoding Regions (for data and parity): Functional Patterns (Do Not Store Data): 1. Position Detection Patterns (Finder Patterns): Three concentric squares positioned at the top-left, top-right, and bottom-left corners. The ratio of module widths is precisely 1:1:3:1:1, allowing camera algorithms to recognize orientation instantly. 2. Separators: White 1-module borders insulating the finder patterns. 3. Timing Patterns: Alternating dark and light module lines connecting the finder patterns along row 6 and column 6, establishing the coordinate grid. 4. Alignment Patterns: Smaller concentric squares embedded in larger QR versions (Version 2+) to correct for lens distortion and curved physical surfaces. 5. Quiet Zone: A mandatory white margin at least 4 modules wide surrounding the entire outer perimeter. Encoding Region (Stores Data & Math): • Format Information: Contains error correction level and masking pattern index. • Version Information: Included in Version 7 and higher. • Data & Error Correction Codewords: Binary modules carrying payload data and Reed-Solomon parity blocks.

QR codes utilize Reed-Solomon algebraic error correction to reconstruct missing or damaged data modules:

How structured QR code URI strings are formatted for native smartphone scanner recognition:

// Generate standard smartphone WiFi onboarding payload string
export function generateWifiQrPayload(
  ssid: string,
  password: string,
  authType: 'WPA' | 'WEP' | 'nopass' = 'WPA',
  hidden: boolean = false
): string {
  const escapeString = (str: string) => str.replace(/([\\;,:"])/g, '\\$1');
  return `WIFI:T:${authType};S:${escapeString(ssid)};P:${escapeString(password)};H:${hidden};;`;
}

// Generate standard MeCard Contact payload
export function generateVCardQrPayload(name: string, phone: string, email: string): string {
  return [
    'BEGIN:VCARD',
    'VERSION:3.0',
    `FN:${name}`,
    `TEL:${phone}`,
    `EMAIL:${email}`,
    'END:VCARD'
  ].join('\n');
}