abs_image — 2D arithmetic op

Data kinds: imageimage

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

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

abs_image: 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

Takes the absolute value of pixel values (`np.abs). Since fullseye's image already follows the [0,1] contract (non-negative), this acts as an identity mapping that changes nothing for a normal image. It only has an effect when a signed intermediate result, such as a difference image, is passed in directly. Stands in for HALCON's abs_image` (Calculate the absolute value (modulus) of an image.).

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

`a, b は未使用。clip 前の生値 v にそのまま abs` を掛けている点に

注意(他の pointwise 分岐は `x = clip(v,0,1) を使うが、この分岐だけ v`

を直接見る)。

Detailed usage guide

gallery2d_gray_arith 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.

abs_image 0.50 0.50

▸ Load this pipeline  ·  Load & run

Runnable examples (verified samples that actually call this op)

gallery2d_gray_arithpy -3.11 examples/gallery2d_gray_arith.py

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

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

Same category (arithmetic)

sqrt_image · exp_image · log_image · sin_image · cos_image · asin_image · acos_image · atan_image


*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.