projective_trans_region — 2D `geometry` op

• Data kinds: region → region

• Call: fullseye.apply(img, "projective_trans_region", 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_region (the HALCON reference is a useful guide to its meaning and parameters)

Usage

Applies the same trapezoidal distortion as `projective_trans_image to a region (binary mask). Since out_sort is region, build() wraps it with _rebinarise, converting the fractional values produced by interpolation back to binary using >0.5 before returning (post-processing so as not to break the region's {0,1} contract). Corresponds to HALCON's projective_trans_region` (Apply a projective transformation to a region.).

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

`a が歪みの強さ、b` が非対称さを振る。両方が使われる。

Detailed usage guide

• gallery2d_geometry 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)

• gallery2d_geometry — py -3.11 examples/gallery2d_geometry.py

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

identity · reg_erode · reg_dilate · reg_open · reg_close · fill_holes · select_largest · remove_small

Same category (`geometry`)

rotate_img · rescale_img · affine_warp · sk_swirl · mirror_image · transpose_region · rotate_image · zoom_image_factor

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

projective_trans_region — 2D geometry op