shape_locate — 2D `matching` op

• Data kinds: image → match

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

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

shape_locate: input → output

*The figure is the actual output on a synthetic 128×128 input. Left: input, right: output. Point clouds are drawn as a top-down scatter (brightness = z), 1-D series as a line plot, volumes as the maximum-intensity projection along z, videos as the middle frame, complex images as magnitude; return values that are not pictures are shown as the values themselves.*

*Knob a does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*

*Knob b does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*

Usage

Template matching that accounts for rotation (shape-based matching). Equivalent to HALCON's find_shape_model (Find the best matches of a shape model in an image.).

a, b are unused — as with _ncc_locate, the template is pre-registered with set_match_template. The template is rotated from 0°〜330° in 30° steps, _ncc_map (NCC) is computed for each, and the best correlation over all positions and all angles is returned as [correlation, y, x, angle]. Because the angle step is coarse (30°), it does not reach continuous angular precision like HALCON's find_shape_model — it is for rough orientation detection. If no template is set, [0,0,0,0].

Detailed usage guide

• gallery2d_contour_measure 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.

shape_locate 0.50 0.50

▸ Load this pipeline · Load & run

Runnable examples (verified samples that actually call this op)

• gallery2d_contour_measure — py -3.11 examples/gallery2d_contour_measure.py

• poc_template_tracking — py -3.11 examples/poc_template_tracking.py

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

identity

Same category (`matching`)

ncc_locate

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

shape_locate — 2D matching op