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QR family

The QR family in this SDK contains three separate runtime formats:

Label id Write Read Geometry
QR Code qr ✅ ✅ Square QR Model 2, versions 1–40.
Micro QR Code microqr ✅ ✅ Compact M1–M4 family.
rMQR Code rmqr ✅ ✅ 32 standard rectangular geometries.

They share broad ideas such as masking and Reed–Solomon error correction, but their function patterns, format information, capacity tables and detectors are different. Do not treat one ID as a spelling variant of another.

QR Code Model 2

The qr module implements the ordinary square QR Model 2 family, versions 1–40 and error-correction levels L, M, Q and H. When no version is forced, the encoder selects the smallest version that fits the payload and the requested options. It can use Numeric, Alphanumeric, Byte and Kanji modes when the input and runtime provide the required character support. Byte handling can use automatic charset selection, UTF-8 or ISO-8859-1.

import {
  decodeQR,
  encodeQR,
} from '@sythos/js_barcode_universal/qr';

const matrix = encodeQR('https://www.sythos.net/', {
  ecc: 'H',
  charset: 'utf-8',
});

const decoded = decodeQR(matrix);
console.log(decoded.text);

The public encoder options are ecc, version, mask, charset and kanji. mask is normally selected by the penalty score; forcing it is useful for fixtures and interoperability work, not usually for application code. The root encode() and decode() functions select this family with format: 'qr' or formats: ['qr'].

The QR reader validates format and version information, unmasks the data, corrects Reed–Solomon blocks and rejects ambiguous or structurally invalid symbols. The image detector can estimate a quadrilateral and sample a symbol from a clean or mildly degraded image. The camera profile retries the fixed eight in-plane orientations at 45-degree steps. That is not a guarantee for arbitrary perspective, curved media, severe occlusion or a multi-symbol scene.

QR Model 1 is not silently treated as Model 2. It is deliberately absent from the registry because the current evidence set does not contain the complete placement figures and fixtures required for a trustworthy writer and reader. See Excluded formats.

Micro QR Code

Micro QR uses a different symbol geometry and a much smaller capacity range. The implementation covers the M1–M4 family and the supported Numeric, Alphanumeric, Byte and Kanji payload paths. The public option set includes a version ('M1' | 'M2' | 'M3' | 'M4'), its legal error-correction level and a mask where applicable.

import {
  decodeMicroQR,
  encodeMicroQR,
} from '@sythos/js_barcode_universal/microqr';

const matrix = encodeMicroQR('12345', {
  version: 'M2',
  ecc: 'L',
});

console.log(decodeMicroQR(matrix).text);

M1 supports numeric payloads but provides error detection only: it has no correctable payload error-correction level in the same sense as M2–M4. ECI, FNC1/GS1 and Structured Append are intentionally outside this API. A normal QR Model 2 symbol must not be relabelled as Micro QR merely because it is small.

The detector accepts clean scaled rasters, inverted polarity and mild projective sampling, with the fixed 45-degree camera orientation retries. It does not claim arbitrary perspective, curved-media or multi-symbol robustness.

rMQR Code

rmqr covers the 32 standard rectangular geometries in the checked-in table. It supports M/H error correction and Numeric, Alphanumeric, Byte and Kanji payloads, plus the implemented ECI path for byte payloads.

import {
  decodeRMQR,
  encodeRMQR,
} from '@sythos/js_barcode_universal/rmqr';

const matrix = encodeRMQR('rMQR SAMPLE', {
  ecc: 'M',
});

console.log(decodeRMQR(matrix).text);

The encoder can be constrained by the available geometry/version options when an installation has a fixed rectangular area. The detector expects a quiet zone and enough scale to resolve modules, and supports the fixed camera orientation retry policy. Arbitrary photographic perspective and multi-symbol scenes remain outside the documented guarantee.

What the three formats do not share

Question QR Model 2 Micro QR rMQR
Symbol shape Square Small square Rectangular
Registry ID qr microqr rmqr
ECC levels L, M, Q, H M1 uses error detection only; M2–M4 use their legal levels M, H
Version/geometry 1–40 M1–M4 32 fixed geometries
ECI/feature scope Charset/byte path as exposed by QR encoder ECI, FNC1/GS1 and Structured Append out of scope ECI byte path implemented; check options for exact payload constraints
Native DENSO SQRC Not included Not included Not included

The table is a product boundary, not a claim that every QR-compatible scanner will accept every variant. An application that needs a vendor-specific feature must use the vendor’s licensed implementation or a separately validated adapter.

ZXing and other independent implementations may be used as black-box verification tools, as recorded in NOTICE.md. No external barcode source code or tables are shipped as runtime dependencies. Standard, patent and trademark questions remain subject to the review labels in LICENSE and the individual files under licenses/.