blend_mode — GFX2D `composite` op

• Data kinds: rgb × rgb → rgb

• Call: import gfx2d; gfx2d.blend_mode(base, top, mode='normal', opacity=1.0) (or opsgfx2d.get("blend_mode"))

Usage

Blend two opaque `rgb` images with a named mode (W3C Level 1).

With an opaque backdrop the specification reduces to a lerp,

`Co = (1 - opacity)*Cb + opacity*B(Cb, Cs), so opacity=0` returns the

backdrop exactly and `mode="normal", opacity=1` returns the source

exactly. Both identities are checked bit-for-bit in the test suite.

Named `blend_mode and not blend because :func:imagemorph.blend`

already owns that name for a two-image cross-fade; two functions called

`blend` with different signatures is exactly the kind of collision this

library's naming test exists to prevent.

Raises ValueError: unknown mode, mismatched shapes, opacity outside

`[0, 1], values outside [0, 1]`.

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)

• gfx2d_scene — py -3.11 examples/gfx2d_scene.py

Ops the type connects to (they accept `rgb` as input)

srgb_to_linear · linear_to_srgb · light_mask · normal_map_decode · bloom · vignette · chromatic_aberration · film_grain

Same category (`composite`)

premultiply · unpremultiply · alpha_composite · alpha_composite_premul · layer_stack

*Provenance: gfx2d.py — GFX2D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

blend_mode — GFX2D composite op