geometry op• Data kinds: image → image
• Call: fullseye.apply(img, "rotate_image", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: rotate_image (the HALCON reference is a useful guide to its meaning and parameters)

*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).*
Rotates the image about its center by `-45 to +45 degrees (determined by a) (scipy.ndimage.rotate, with reshape=False to keep the canvas size unchanged). Areas that fall outside the frame are filled by reflection (mode="reflect"), so the four corners show a folded-back copy of the original image (a known design constraint that makes it unsuitable as-is for uses like document skew correction where you want the out-of-frame area filled with a background color). Corresponds to HALCON's rotate_image` (Rotate an image about its center).
> The detailed description below is the original text — the summary and the headings are translated.
`a が回転角を -45°〜+45° の範囲で振る。b` は未使用。
• gallery2d_geometry family guide
• 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.
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.
rotate_image 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_geometry — py -3.11 examples/gallery2d_geometry.py
image as input)identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter
geometry)rotate_img · rescale_img · affine_warp · sk_swirl · mirror_image · transpose_region · zoom_image_factor · zoom_image_size
*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.