tac_shear_field — 2D tactile op

• データ種: image → image

• 呼び出し: fullseye.apply(img, "tac_shear_field", a=0.5, b=0.5) (2-D は 1 画像 + 2 スカラつまみ a,b∈[0,1] のモデル)

使い方

In-plane shear proxy from the 2-D structure tensor (Foerstner /

Bigun-Granlund orientation coherence). The tensor

`J = G_sigma(grad v * grad v^T)` has eigenvalues l1 >= l2, and the

coherence `(l1-l2)/(l1+l2) = sqrt((J11-J22)^2 + 4*J12^2) / (J11+J22)`

is 1 where the gel texture is stretched into a single dominant orientation

(as it is under tangential/shear load) and 0 where it is isotropic. The

result is additionally weighted by the tensor trace (gradient energy) so

that texture-free, un-contacted gel stays dark instead of amplifying noise

orientation. `a = tensor integration sigma (0.6..4.6), b` = output gain

(0.5..2.5). Output clipped to [0,1], HxW; a constant frame has zero gradient

energy and yields an all-zero shear field.

参考(サンプルデータ・文献)

• サンプルデータ カタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。

• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。

実行できる例(この op を実際に呼ぶ検証済みサンプル)

• sim2real_and_alife — py -3.11 examples/sim2real_and_alife.py

型が繋がる次の op(image を入力に取れる)

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

同カテゴリ(tactile)

tac_contact_mask · tac_height_from_shading · tac_surface_normal · tac_pressure_proxy

*Provenance: ops.py — 2D operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。*

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