Transparent Signature from a Photo

Signing a document digitally is often just a matter of placing an image of your signature on it, but a photo of a signature on paper has a grey, uneven background that looks wrong on a white page. This tool turns that photo into the signature alone: clean ink lines on a transparent background.

Uneven light and phone shadows are evened out first by comparing each pixel with the paper around it, so the background disappears even in a dim photo. Ink detection is automatic and can be tuned: keep faint pen strokes or only the darkest lines. The ink can be recoloured to pure black, blue or dark blue (as with a ballpoint pen) or left as photographed; edges are smoothed and thin lines can be made bolder. The result is trimmed to the signature with a small margin.

Because a signature is sensitive, this matters most here: the photo is processed entirely by your browser and never uploaded. The same steps work for stamps, hand-drawn sketches and notes.