xcv2_warp_logpolar — 2D `geometry` op

• Data kinds: image → image

• Call: fullseye.apply(img, "xcv2_warp_logpolar", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

xcv2_warp_logpolar: 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

Maps the image onto a (radius, angle) plane using the log-polar transform.

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

`cv2.warpPolar の WARP_POLAR_LOG` モードを使う。中心は画像中心、最大

半径は `min(H, W)/2`。出力の行方向が対数半径、列方向が角度に対応する。

`a, b` は未使用。拡大縮小・回転を新しい画像上の平行移動に変換できる

ため、テンプレートマッチングの前処理（Fourier-Mellin 変換の要素技術）として

使われる。HALCON に対応する単一オペレータは無い。

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.

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.

xcv2_warp_logpolar 0.50 0.50

▸ Load this pipeline · Load & run

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 `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).*

xcv2_warp_logpolar — 2D geometry op