Rasterlessvector

Two colours, one clean silhouette contour

Black and white sounds like a reduction. For a whole family of jobs it is the opposite: it is the only shape the job accepts. A vinyl cutter pulls one blade through one sheet of film, so artwork has to be a region and its complement. A stencil is material and holes; a screen separation is one ink per screen; a laser runs one power per layer; single-colour embroidery is thread or nothing; a rubber stamp is raised or flat. Two states each — and artwork arriving with forty is artwork somebody must flatten by hand.

Setting Colours to 2 does that flattening in the right place: during segmentation, not afterwards. The tracer clusters pixels in LAB space; ask for two and k-means finds two centres and assigns every pixel to the nearer one. Only then does the edge model read the anti-aliased pixels on the border between them, slide that border onto its sub-pixel position and fit a curve. One boundary, one contour per connected shape. At 26 colours the same image also returns the halo of in-between greys around that shape, each grey its own closed path where the machine wanted one.

If you have come from a tracer whose main dial is a brightness threshold — drag left and the shape fattens, drag right and it thins — the honest answer is that this converter has no such dial, and no separate knob for rounding corners. The colour count is the control, and the clustering decides where the split falls.

Drop an image here

or click to choose one

PNG · JPG · WEBP

How it works

  1. Upload one PNG, JPEG or WEBP — one image per conversion, up to 25 MB and 40 megapixels.
  2. Drag Colours down to 2. That single setting is the whole black-and-white control.
  3. Pick the output your next machine reads: SVG for cutters and sign software, DXF R2010 for a laser or CAD, or both.
  4. Check the 800 px preview. If the split landed in the wrong place, raise the contrast in the source image and run it again.
  5. Sign in with Google (free) and download the files.
A silhouette PNG and its two-colour vector: one closed contour around the shape instead of a rim of stepped greys. — source image A silhouette PNG and its two-colour vector: one closed contour around the shape instead of a rim of stepped greys. — vector result
A silhouette PNG and its two-colour vector: one closed contour around the shape instead of a rim of stepped greys.

Who this is for

Most people here did not choose monochrome — the machine downstream chose for them, and they want a file that will not argue with it. A sign shop has a logo and a roll of film; a printer has screens and one ink per pull.

The failure to avoid is tracing in colour and tidying up afterwards. A high-count trace of a black mark on white paper gives you the shape ringed by greys, and in cutting software every ring is another path to cut. Delete them by hand and the outer edge has moved, because the ring you kept was never the outermost one. Two colours settle that boundary once, where the anti-aliasing ramp is half of each side.

One thing it will not do is add bridges. If a design has a counter — the middle of an O — the trace reports it honestly as a hole, and a hole in a stencil is a piece that falls on the floor. Put the bridges into the artwork before converting.

Settings we suggest

Colours: 2. The slider runs 2 to 64 and opens at 26; dragging it to the bottom is the entire black-and-white setting. Two cluster centres, one border, one fitted contour per connected shape.

To move where that border falls, edit the source raster before uploading. Levels or a contrast bump change which pixels join which cluster — the same steering a threshold number would give you, applied one stage earlier. A soft, evenly lit photograph is the hard case.

Draw style: Fill shapes gives two filled regions — what a blade, a screen and a stamp plate all want. Stroke edges is worth knowing for engraving: it draws only the border between the two regions, once, as a line to follow rather than an area to flood. Shape stacking: Cut-outs, so an enclosed shape is subtracted from the one around it and arrives as a real hole.

The millimetre fields fix the physical size in every vector format the job is likely to reach for: the SVG width and height, the DXF coordinates, and the page box of the PDF and the EPS, converted to points — ask for a 150 mm cut line and it comes out 150 mm wide in all four. The DXF states that unit in its own header too, so a cutting program opens it at size instead of asking. Left empty, SVG and DXF are read at 96 pixels = 25.4 mm and the PDF and EPS pages take the traced pixel dimensions as points.

Questions

I am used to dragging a threshold. What replaces it here?

The colour count. There is no threshold in this panel and nothing to dial in by feel — choosing 2 colours is the decision, and the clustering places the boundary. If that is not the division you wanted, change the source image: a levels or contrast adjustment decides which pixels join which cluster.

Will two colours give me literal black and white?

Not always. Both centres are computed from your image, so a navy crest on cream paper comes back as navy and cream — two tones, one contour, structurally the same thing. If the file has to be #000000 and #FFFFFF, recolour the two paths in your editor or desaturate the source first.

What happens to a transparent background at two colours?

Transparent stays empty. Pixels with alpha above 10 count as the picture, so the vector holds the silhouette and no background rectangle; partly transparent pixels are flattened onto white before tracing. One quirk: the preview renders on white, so a pale silhouette looks blank there while the downloaded file is fine.

Which file do I send to a cutter or a laser?

SVG for vinyl cutters and sign software — closed paths, and paths only. DXF R2010 (AC1024) for LightBurn, Fusion 360 or AutoCAD 2010 and later; it holds outlines, LWPOLYLINE plus degree-3 SPLINE, never a HATCH, on one layer per colour — two at most here. Coordinates sit at millimetre scale and the header declares that unit ($INSUNITS = 4), so LightBurn or Fusion 360 opens the contour at size rather than asking you to name a unit.

Is a two-colour job quicker, and what happens to my upload?

Not reliably: cost tracks how much fine detail the picture holds rather than palette size, and stencil work is often detailed. Logos and stickers typically convert in 3–12 seconds in our local measurements; fine-line or noisy images take longer, and a conversion that has not finished after 60 seconds stops and suggests fewer colours or a smaller image — at 2 colours, a smaller image is the lever. It is free and unwatermarked: study the preview, then a free Google sign-in releases the files, lifting you from 10 conversions per hour to 60 per hour and 300 a day. Download links expire after 1 hour; uploads and generated files go under an automatic 1-day deletion rule.

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