bloom — GFX2D post op

• 数据种类:rgb → rgb

• 调用:import gfx2d; gfx2d.bloom(rgb, threshold=0.8, sigma=4.0, intensity=0.6)(或 opsgfx2d.get("bloom"))

用法

让图像的明亮部分向周围渗出。

> 以下的详细说明为原文 —— 摘要与标题已翻译。

The classical three steps: isolate what is above `threshold`, blur it by a

Gaussian of `sigma, add intensity` times the result back, clip.

A *linear-light* operator: light spreading in a lens adds radiance. Running

it on sRGB-encoded values makes the halo too strong in the mid-tones —

`srgb_to_linear first, linear_to_srgb` after.

Exact identities: `intensity=0 and threshold >= 1` both return the

input bit for bit, and a black image stays black.

The added energy is *not* conserved by the clip at the end. The suite

measures both halves: on a centred bright blob the Gaussian preserves the

bright mass to 5.0e-16 relative, so everything lost after that is the

clip — on a random scene with a saturated square, 2.69 % of the pixels clip

and 1.65 % of the total energy is thrown away, and neither number is

returned to the caller.

参考(示例数据・文献)

• 示例数据目录(下载 URL / 许可证) —— 2-D 用 skimage.data(BSD/公有领域)加合成图,3-D 给出真实数据源(Stanford/PDS 等)的下载 URL。

• 算子来历与参考文献 —— 该算子族所依据的研究/方法出处。

• 算法的正典(作者・年份)与用途见上面的族使用指南。

可运行的示例(实际调用该算子并已验证的样例)

• gfx2d_scene — py -3.11 examples/gfx2d_scene.py

类型可衔接的下一个算子(可接受 rgb 作为输入)

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

同类别(post)

vignette · chromatic_aberration · film_grain · color_lut · color_grade · dither · palette_quantize

*Provenance: gfx2d.py — GFX2D 算子登记表。本条目由 tools/opdocs.py md 自动生成(请勿手工编辑)。*

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