vectorize

name	vectorize
description	Convert a raster image to SVG. Three paths — Recraft hosted vectorization, vtracer (multi-color polygon), potrace (1-bit). Optimizes with SVGO; validates path count as a quality signal.
trigger_phrases	["vectorize","convert to svg","trace image","raster to vector","svg from png"]

Vectorize

Three paths

1. Recraft /vectorize (hosted, highest quality)

Input: any raster. Output: clean SVG, typically 20–100 paths for a mark, 200–500 for an illustration. Commercial tier only.

const svg = await recraft.vectorize({ image: pngBuffer });

2. vtracer (local, multi-color polygon)

• Rust binary; npm install vtracer for the Node wrapper.
• Modes: polygon (recommended for logos), spline (smoother curves), pixel (blocky).
• Color count controlled upstream via K-means quantization before vectorization.

pipeline:
  raster 1024²
  → BiRefNet matte (alpha the background)
  → K-means LAB 6-color palette
  → vtracer --mode polygon --filter-speckle 4 --color-precision 6
  → SVGO (conservative preset)

3. potrace (local, 1-bit)

• Classical Stan Ford vectorizer; binary output only (no color).
• Best for: icon packs (single-color), typography work, line art.
• Multi-color workaround: separate each color into its own 1-bit layer, vectorize each, stack SVG <g>s.

pipeline:
  raster 1024²
  → BiRefNet matte
  → per-color mask (binary threshold per palette entry)
  → potrace per mask → <g> wrapper
  → combine into single SVG
  → SVGO

Choosing the path

Use case	Path
Budget available, one-shot quality	Recraft vectorize
Multi-color logo, local	vtracer (polygon mode)
Single-color icon pack	potrace
Photorealistic illustration → vector	don't — keep as PNG/WebP. Vectorization of photoreal is lossy noise.

Path-count quality signal

After vectorization, count <path> elements:

• ≤40 paths → clean, production-ready mark.
• 40–200 paths → likely acceptable; scan for overlapping slivers.
• >200 paths → probably bad. Either the input has noise (regenerate), too many colors (reduce K-means), or the subject is inappropriate for vectorization (keep as raster).

SVGO configuration

Conservative preset — preserve: viewBox, IDs, classes. Strip: metadata, editor comments, hidden elements.

{
  multipass: true,
  plugins: [
    { name: 'preset-default', params: {
        overrides: { removeViewBox: false, cleanupIds: { minify: false } } } },
    'removeDimensions',     // prefer viewBox-only
    'sortAttrs',
    'removeScriptElement'   // security
  ]
}

Never enable convertPathData with default floatPrecision — it collapses small strokes.

Validation

• SVG parses with @resvg/resvg-js without errors.
• <path> count ≤ 200 for logos, ≤ 500 for illustrations.
• No <image> tags (sneaking raster into SVG).
• No <script> tags.
• viewBox present.
• Rasterized at 1024 × 1024 should be visually identical (SSIM > 0.95) to source raster.

Output

vector/
├── mark.svg         # primary vectorization
├── mark.svg.orig    # pre-SVGO original (for debugging)
└── meta.json        # paths_count, colors_used, svgo_savings_bytes