@ybelik/scene-tracer

Image → traced SVG, auto-tuned. The trace stage of the ybelik pipeline (generate → trace → compile → reveal — see the root README): a deterministic layer_difference ladder walks the trace until the path count lands in the jank-safe band, then the result is ready for @ybelik/scene-compiler.

The vector core is visioncortex vtracer via wasm_vtracer — CLI-parity verified on real photographic input (identical path count and render vs the native vtracer CLI). Succeeded the project's Python trace_scene.py on 2026-07-16.

CLI (Node)

npx @ybelik/scene-tracer image.png scene.svg
# or with a custom band / ceiling:
npx @ybelik/scene-tracer image.jpg scene.svg --min 1500 --max 3500 --max-kb 2048

Prints the chosen cell, the ladder it walked, and any flag; writes a scene.settings.json sidecar — the full reproduction recipe (settings-are-data). PNG and JPEG in; SVG (with viewBox) out.

Browser (ESM, no build step)

import * as glue from 'https://cdn.jsdelivr.net/npm/[email protected]/wasm_vtracer_bg.js';
import { initTracer } from 'https://cdn.jsdelivr.net/npm/@ybelik/[email protected]/scene-tracer.js';

const tracer = await initTracer({
  glue,
  wasm: 'https://cdn.jsdelivr.net/npm/[email protected]/wasm_vtracer_bg.wasm',
});
const { svg, settings } = tracer.traceScene(imageData.data, imageData.width, imageData.height);

The visitor's device pays the CPU (~1–3 s per ladder step at 1024 px); nothing uploads.

Policy

DEFAULT_POLICY — color_precision: 8 (pinned) · ld_ladder: [8,16,24,32,48,64] · target_paths: [1500, 3500] · max_kb: 2048 · downscale_px: 1024. Override any key via traceScene(..., { policy }). Flags: band-edge · over-ceiling · chunky-by-content (features, not failures). The numbers' home — rationale and acceptance criteria: TRACE-SETTINGS.md.

MIT · part of the ybelik story engine.