Image Signature Maker

How the signature maker works

Draw uses the open-source signature_pad library. Each stroke is stored as points with timestamps and drawn as smooth curves through them. Like a real pen, the line gets thinner when you move faster. With a stylus that reports pressure, pressing harder also makes the line wider. Because the strokes are kept as points rather than pixels, the tool can redraw them sharply at 2× or 3× size, after the window is resized, and as an SVG file.

Upload turns the paper transparent. Every pixel gets a brightness from 0 (black) to 255 (white):

• pixels at or above the threshold become fully transparent;
• pixels clearly darker than the threshold stay solid;
• pixels in between fade out, so the edges of the strokes stay smooth instead of jagged.

The automatic setting uses Otsu's method, which picks the brightness that best separates the pixels into two groups, ink and paper. Keep original keeps the colour of your pen; Black and Blue replace it with one solid colour. Remove small specks clears isolated dots of dust or paper grain.

In both modes the download is trimmed to the signature plus the padding you choose (at 2× and 3× the padding grows with the drawing).

For example, a 4,000 × 3,000 pixel phone photo is processed at 3,000 × 2,250 pixels. If the signature covers 1,200 × 400 pixels of it, the PNG with 10 px padding is 1,220 × 420 pixels.

Getting a clean photo or scan

• Sign on plain white paper with a dark pen. A gel or felt-tip pen gives stronger lines than a ballpoint; pencil is often too faint.
• Take the photo in daylight or even light, holding the phone flat above the page so no shadow falls on it.
• Fill most of the picture with the signature; keep the paper’s edge and the table out of view.
• A flatbed scan gives the cleanest result.
• If shadows or paper texture remain, lower the threshold. If thin strokes break up, raise it.

Using your signature image

• PDFs and forms: use your PDF editor's option to add an image or a signature, place it on the signature line and save. The transparent background lets the lines of the form show through.
• Word and Google Docs: insert the PNG as a picture and set it in front of the text so you can move it onto the signature line.
• Email signatures: most email programs let you add an image to your signature. Resize it to a modest width first.

A signature image is not a digital signature

A drawn or scanned signature is just a picture. It carries no certificate, does not prove who added it to a document and does not show whether the document was changed afterwards. Anyone with the file can copy it, so keep it to yourself.

In India, the Information Technology Act, 2000 recognises digital signatures backed by a Digital Signature Certificate (DSC) from a licensed Certifying Authority, and electronic signatures such as Aadhaar eSign. A pasted image is neither. Many people accept a signature image on everyday letters and forms, but where a digital signature is required, only a certificate-based one will do. Company filings on the MCA21 portal, for example, must be signed with a DSC. If in doubt, ask the recipient what they accept.

Privacy

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