# Raster Artwork to SVG

> Trace logos and flat artwork into real SVG paths with a limited color palette. Upload a PNG, JPEG or WebP and trace sampled pixels into editable polygonal SVG paths. Set color count or a custom palette, switch to black and white, remove a border color and drop small regions. The file tool uploads to the server; Lumina Vector Lab runs locally.

Part of usefulweb.app (https://usefulweb.app/). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://luminarastervectorizer.usefulweb.app/ (interactive tool at https://luminarastervectorizer.usefulweb.app/tool)
- JSON API: POST https://luminarastervectorizer.usefulweb.app/api/v1/calculate with a JSON object of inputs (schema: https://luminarastervectorizer.usefulweb.app/api/v1/tool)
- OpenAPI: https://luminarastervectorizer.usefulweb.app/openapi.json
- MCP (Streamable HTTP): https://luminarastervectorizer.usefulweb.app/mcp - tool `lumina_raster_vectorizer`

## Inputs
- image (file, required): Image (PNG, JPEG or WebP; 8 MB, 16 MP maximum)
- mode (select): Tracing mode
- colors (number): Automatic color count
- resolution (select): Longest sampled side (pixels)
- threshold (number): Black / white threshold
- alpha (number): Minimum visible alpha
- minArea (number): Drop regions smaller than this pixel count
- background (select): Background
- palette (text): Custom HEX palette (optional; 2–16 colors)

## Method
- Exact polygonal outlines of sampled pixels; collinear vertices are removed. No bitmap is embedded in the SVG. Curves are not fitted.
- Colors use nearest Euclidean encoded-sRGB distance. Alpha is thresholded to opaque or transparent. Small connected regions are dropped to transparency, not merged.
- Border removal deletes every region of the most frequent opaque border color, including interior regions of that color. Ties use the first palette color.
- At most 512 pixels per side, 2048 shapes and 60000 nodes. Use logos, icons or flat artwork; photographs may need fewer colors and lower sampling.
- Decode the first image, auto-orient, convert to 8-bit sRGB, and downsize to 512 pixels per side before nearest-center sampling. Automatic colors reuse Lumina Palette Studio histogram extraction. Four-connected flood fill labels each region, directed boundary edges form closed rings, and even-odd fill preserves holes.