projective_trans_contour_xld — 2D `contour` op

• Data kinds: contour → contour

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

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

projective_trans_contour_xld: 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

Applies a pseudo perspective-shrink depending on column position to each point of the contour (dividing each point's coordinates by `d = 1 + 0.3*a*(col - center)/width). Note that this is an approximation using a simple one-directional scale change rather than a true projective transformation via a 3x3 homography matrix. A stand-in for HALCON's projective_trans_contour_xld` (Apply a projective transformation to an XLD contour.).

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

`a が収縮の強さを振る。b` は未使用(画像版の

`projective_trans_image とは異なり、この輪郭版は b` を使わない)。

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.

threshold 0.50 0.50
sk_find_contours 0.50 0.50
projective_trans_contour_xld 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

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

identity · select_contours · smooth_contours · fit_line_contours · contours_to_region · count_contours · total_length · select_contours_xld

Same category (`contour`)

select_contours · smooth_contours · fit_line_contours · contours_to_region · sk_find_contours · edges_sub_pix · lines_gauss · select_contours_xld

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

projective_trans_contour_xld — 2D contour op