decode_barcode — 2D barcode op

Data kinds: imagefeature

Call: fullseye.apply(img, "decode_barcode", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

HALCON equivalent: find_bar_code (the HALCON reference is a useful guide to its meaning and parameters)

decode_barcode: 入力 → 出力

*The figure is the real output on a synthetic 128×128 input. Left: input, right: output (a non-image return value is shown as the value itself).*

Usage

A simplified barcode-like feature that counts the number of light/dark transitions along the central scan line. This resembles but is not the same as HALCON's `find_bar_code` (Detect and read bar code symbols in an image.) - it performs no symbology determination or data decoding whatsoever (it only counts the "number" of bars).

> The detailed description below is the original text — the summary and the headings are translated.

`a が「暗い」とみなすしきい値を 0.3〜0.7 に振る。b は未使用。画像中央の行(v.shape[0]//2)だけを見て、v < しきい値` の画素を 1 とした列に対し、0→1 に立ち上がる回数(暗いバーの本数)を数える。実際のバーコードのデータ(数字・文字列)は得られない。

Detailed usage guide

gallery2d_physics_alife_3d family guide

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Try it in Studio

The program below has been verified to run (same input as the figure). In Studio's help this block becomes buttons that load and run it on the spot.

decode_barcode 0.50 0.50

▸ Load this pipeline  ·  Load & run

Runnable examples (verified samples that actually call this op)

gallery2d_physics_alife_3dpy -3.11 examples/gallery2d_physics_alife_3d.py

poc_barcode_1dpy -3.11 examples/poc_barcode_1d.py

Ops the type connects to (they accept feature as input)

identity

Same category (barcode)


*Provenance: ops.py — 2D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.