# sz3/libcimbar

Optimized implementation for color-icon-matrix barcodes

Repository: https://github.com/sz3/libcimbar
Canonical: https://ross.abutalabs.com/products/libcimbar
Homepage: https://cimbar.org
Language: C++
License: MPL-2.0
License Family: copyleft
Topics: opencv, barcode, fountain-codes, proof-of-concept, image-hash, cpp17
Last push: 2026-08-21T23:35:38+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 98, release rhythm 87, longevity 100
- inputs: {"age_days": 2337, "days_push": 12, "days_rel": 7, "gap_med": 63, "n_releases_24m": 6}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 6426, forks 471 (observed 2026-08-28T04:09:43.348383+00:00)

## What it is
libcimbar is an optimized C++ implementation of the cimbar (color icon matrix) high-density 2D barcode format for air-gapped data transfer via screen-to-camera video. It encodes files up to 33MB into animated barcodes using fountain codes, zstd compression, and Reed-Solomon error correction, achieving ~850 kbit/s over a monitor and phone camera.

## Use cases
- transfer files to an air-gapped computer using only a screen and camera
- encode a file into animated barcode images
- decode cimbar barcodes with a phone camera to reconstruct a file
- send data between devices without internet, bluetooth, or NFC
- build applications that read or write cimbar barcode formats

## When to choose
- you need one-way data transfer into an air-gapped or network-isolated machine
- you want high-throughput optical data transfer without any radio or network channel
- you need a barcode format that tolerates out-of-order, missing, or corrupted frames

## When to avoid
- you need a simple, widely-supported barcode like QR codes for small payloads
- you require real-time bidirectional communication
- your environment cannot display animated video or capture it with a camera

## Facets
- artifact type: library
- maturity: active
- function: serialization, image-processing, computer-vision, compression, error-handling
- domain: computer-vision, image-processing, files, privacy, developer-tools
- platform: browser, wasm, cpp, cross-platform
- tags: barcode, fountain-codes, air-gapped-transfer, reed-solomon, opencv, data-transfer, qr-code-alternative, linux, android

## Member repositories
- sz3/libcimbar (main) score 95

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:43.348383+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:44:53.341835+00:00, confidence not recorded.
  - readme: https://github.com/sz3/libcimbar (fetched 2026-08-28T04:09:43.348383+00:00, sha f64463faf2e0)
  - homepage: https://cimbar.org (fetched 2026-08-29T08:41:35.422937+00:00, sha 009347b03b4b)
- Data as of 2026-08-30T08:39:29.467469+00:00.