dm_locate — SYMBOL `datacode2d` op

• Data kinds: image2d → table

• Call: import fullseye as fs; fs.ledger.dm_locate(image) -> 'dict' (to call the implementation directly, import dmsym; dmsym.dm_locate(image) -> 'dict'; from the registry, opssymbol.get("dm_locate"))

• GPU: none (CPU reference implementation only)

Usage

Find a Data Matrix in an image and estimate the module-space to image homography (table).

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

Locate a dark-on-light ECC200 symbol (quiet zone >= 1 module). Global binarisation (Otsu start, then the midpoint of the dark/light means), dark pixels grouped after a distance-based closing at several radii (so separated dot-peen dots join), near max-area quadrilateral in the convex hull, sub-pixel edge lines (grey-level threshold crossings, inward outliers from the clock gaps trimmed), corners = line intersections, then the size and which corner is the L corner are chosen by the agreement of the sampled function pattern (finder + clock + alignment) for every supported size and corner correspondence.

Returns

dict

homography 3x3(module 空間 [x=列, y=行, 1] → 画像 [列, 行, w])、rows, cols,

corners (4, 2) 画素の (行, 列)、順は module 空間の (0,0), (C,0), (C,R), (0,R)、

module_px, score(機能パターンの一致率), threshold(大域閾値 / global threshold)。

Raises

ValueError

2-D でない・NaN/inf・小さすぎる。

DMDecodeError

記号が見つからない。

Detailed usage guide

• symbol_reading 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.

Runnable examples (verified samples that actually call this op)

• poc_symbol_part_dpm — py -3.11 examples/poc_symbol_part_dpm.py

Ops the type connects to (they accept `table` as input)

render_symbol · symbol_read_trials · symbol_read_pod · ocr_classify · ocr_read_line · ocr_read_trials

Same category (`datacode2d`)

qr_encode · qr_decode_modules · qr_locate · qr_sample · qr_read · dm_encode · dm_decode_modules · dm_sample

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

dm_locate — SYMBOL datacode2d op