projective_trans_image — 2D geometry op

Data kinds: imageimage

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

Usage

Perspective (projective) transformation (`cv2.warpPerspective). Creates a trapezoidal (perspective-distorted) warp by pulling the top two of the four corners inward by a ratio of d=0.06+0.12*a. Areas outside the frame are filled by reflection. Corresponds to HALCON's projective_trans_image` (Apply a projective transformation to an image.) (HALCON can take an arbitrary homography matrix, but this is an approximation limited to a single trapezoidal-distortion pattern).

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

`a が歪みの強さを、b` が左右の非対称さ(どちら側をより歪ませるか)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_geometrypy -3.11 examples/gallery2d_geometry.py

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

identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter

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).*

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