How to use it
Photograph your signature with a dark pen on plain white paper in even light, drop the picture here and set the width, height and file-size limits from your form. A frame with the target's shape appears over the picture; drag to position it so the signature fills the frame, zoom in, rotate if the photo is sideways, or fit the whole picture inside with margins. The preview shows the actual output, and the tool reports its pixel size and exact file size in KB.
The clean-up option stretches the brightness range so that grey paper becomes white and the ink becomes darker, which makes the signature easier to read and also compresses to a smaller file. File size limits are met by lowering JPG quality, using 1000 bytes per KB for the maximum and 1024 for the minimum so the file passes either convention. If a clean signature compresses below a required minimum, the pad option adds invisible filler data without changing the image. If the pixel size and KB limits cannot be met together, the tool says so.
Presets are commonly published values for signatures, thumb impressions and declarations and are only starting points: forms change between exams and years, so use the numbers on your own notification and edit any field. Nothing is uploaded. For passport-style photos use the Passport Photo Resizer, for general resizing the Image Resizer, to shrink pictures the Image Compressor, and to attach several scans as one document use JPG to PDF Converter.
Supported formats and limits
| Target size | Any width and height in pixels, cm, mm or inches (DPI 36–1200, up to 6000 px per side). |
|---|---|
| File size | Optional minimum and maximum in KB, applied as 1024 and 1000 bytes per KB; optional padding to reach the minimum. |
| Clean-up | Optional levels adjustment that whitens the paper and darkens the ink; on by default for signatures. |
| Output | JPG (default) or PNG. |
| Presets | Commonly published sizes for signatures, thumb impressions and handwritten declarations, as starting points only. |
| Not included | No handwriting recognition and no check that a signature matches any record; the tool cannot confirm a portal will accept it. |
Practical examples
A signature photographed on a notebook page
- Situation
- Choose the 140 × 60 px, 10–20 KB preset, drop the photo and drag the frame over the signature.
- What to expect
- The paper turns white, the ink darker, and the file is exactly 140 × 60 pixels. A signature on white paper compresses very small, so padding may be used to reach a required minimum.
A 4.0 × 2.0 cm signature at 300 DPI
- Situation
- Choose the 4.0 × 2.0 cm preset and set the maximum size to 20 KB.
- What to expect
- The target is 472 × 236 pixels. The result panel shows the exact size in KB and whether it sits within the range.
A cluttered photo
- Situation
- A signature photographed in uneven light with a shadow across the page.
- What to expect
- Clean-up helps but cannot fix strong shadows. For the best result, photograph on plain white paper in even light and crop closely.
The numbers behind it
pixels = (cm ÷ 2.54) × DPI, e.g. 4 cm × 2 cm at 300 DPI = 472 × 236 pxclean-up: new value = (old value − dark point) × 255 ÷ (paper point − dark point)
- The dark point is the brightness below which only the darkest 3% of pixels fall
- The paper point is the brightness above which the brightest 20% of pixels sit
Stretching the brightness range turns grey paper white and makes ink darker, which also compresses to a smaller file.
Honest limits
- Presets are commonly published values, not rules; confirm every figure with your own notification.
- The tool changes size, brightness and file size only; it cannot verify that a portal will accept the signature.
- Strong shadows or very dark paper limit what the clean-up can do.
- Padding adds invisible filler data to reach a minimum size.