--- title: "Signature Cleaner – White Background, Dark Ink, Exact Size" description: "Turn a phone photo of your signature into clean dark ink on white paper, cropped tight and sized in pixels and KB for any online form. Free." url: "https://imagecompressor.si/signature-cleaner" lang: "en" --- # Clean up a photographed signature Shadows, grey paper and notebook lines go; the ink stays, cropped close and sized for your form. ## How it works 1. **Add your images** Drag and drop, paste, or pick files. They upload over an encrypted connection. 2. **Pick a quality or a target size** Use the quality slider, or tell it exactly how many KB or MB you need. 3. **Download** Save each file, or grab them all at once as a ZIP. A signature photographed on a desk rarely looks like a scan. The paper comes out grey or yellow, one side sits in the shadow of your hand or phone, and the frame holds far more table than ink. Upload portals then reject it as unclear, or the reviewer sees a smudge. This cleaner fixes the picture itself: it works out how bright the paper is in every part of the photo, divides that away, and keeps only what is clearly darker than its own surroundings. After cleaning, the tool finds the box around the ink and crops to it with a slim margin, ignoring a stray speck of dust near the edge. Then it fits that box inside the width and height you typed, centred on white, without stretching it or cutting any stroke off. The KB fields work as on our other form tools: the weight is brought under the maximum by quality alone, and padded up to a minimum if one is set. The size fields start on a placeholder of 300 by 100 pixels. Replace it with the numbers in your application's instructions, because every portal sets its own and we do not guess them. The picture is processed on our server and the upload is not kept; nothing is stored unless you download the result. ## What the cleaner does to your photo Paper is rarely evenly lit, so a single brightness cut-off would leave the shadowed corner grey and wash out the bright one. The cleaner instead measures the paper in a grid of small regions, fills in regions covered by ink from their neighbours, and smooths the result into a map of the sheet's lighting. Dividing the photo by that map makes the whole sheet equally white. On the flattened picture it picks the level that best separates ink from paper, and gives the strokes a short soft edge so they do not look jagged when they are made small. Faint pale lines, such as the blue rules of a notebook page, are lighter than ink and fall on the paper side, so they usually disappear. ## Black ink or the pen's colour Black is the default, because most forms ask for a signature that reads clearly in black and white and many are printed that way. If your instructions ask for blue ink, or you want the signature to look as you wrote it, choose "Pen's colour". The tool then averages the colour of the darkest strokes and deepens it a little, so a light ballpoint still reads as firm ink. ## Getting a photo the cleaner can work with Sign large on plain paper with a dark pen, and photograph it from straight above in daylight. The cleaner copes with shadows and tint, but not with a blurred picture: if the strokes are soft in the photo, they will be soft in the result. Keep other writing away from the signature, or drag the frame so only the signature is inside it, since everything dark in the frame is treated as ink. If the result warns that it found almost no ink, the pen was probably too faint or the photo is out of focus. Sign again with a darker pen and retake the photo. ## Frequently asked questions ### Will the cleaned signature be accepted by my form? It gives you what reviewers expect to see: dark strokes on white with nothing around them, at the size and weight you entered. Whether a given portal accepts it depends on its own rules, so copy the figures from its instructions and read them through once more before you submit. ### Is my signature stored anywhere? The photo is sent to our server to be processed and is deleted when the result is made. We do not keep uploads, and we do not send them to any other company. ### Why is my signature smaller than the box? A signature is wide and low, but the form's box may be a different shape. The whole signature is fitted inside without cropping, so on one side there is white space. Changing the box to a shape closer to your signature fills it more. ### Can I get a transparent PNG instead? This page makes a white background, which is what upload forms ask for. For a signature to place on a document, use the background remover's signature page, which can leave the paper transparent. ### Does it remove the lines of a ruled notebook? Thin light lines usually vanish, because they are much paler than ink. Dark or thick lines, or lines drawn in the same pen, stay. Signing on blank paper avoids the question. ### What if my form gives the size in centimetres? Choose centimetres or millimetres in the unit list and enter the resolution the form names, often 200 or 300 DPI. The tool works out the pixels and records the resolution in the file. ## Related tools - [Resize a signature image](https://imagecompressor.si/signature-resize): Type the width, height and KB limits from your form, and get a signature file that fits them. - [Remove the background from a signature](https://imagecompressor.si/remove-background-from-signature): Photograph your signature on paper and get it as a transparent PNG for documents. - [Compress an image to 20 KB](https://imagecompressor.si/compress-image-to-20kb): Hit a strict 20 KB limit for forms, ID photos or slow-loading pages.