Signature PNG, localized in Simplified Chinese as “签名抠图,” turns a paper signature from a photo or file into a transparent PNG. Signature extraction and editing run on the device, and the app does not upload the source image or signature.
Support email: dingronghui@163.com
When sending feedback, include the app version, iOS version, device type, the steps you followed, and the exact error message. To protect privacy, the app does not attach a signature image automatically. Attach only a redacted or fictional sample that you are authorized and comfortable to share.
Quick start
- Choose Import from Photos or Import from Files on the home screen. The current version has no direct camera entry point.
- Rotate the image if needed, adjust the four page corners, and select a region that contains the complete signature.
- Adjust background removal and ink strength, then inspect the result on checkerboard, white, and black backgrounds.
- If needed, repair strokes with Erase or Restore and use undo, redo, and zoom to inspect details.
- Open Export, choose Original or Document size, and then save to Files or Photos, copy the PNG, or use the system Share Sheet.
Frequently asked questions
1. Why is there a small transparent margin around the exported signature?
This is intentional safety padding. The app trims large transparent areas from the final Alpha bounds, then keeps max(12 px, 4% of the signature’s short side) around meaningful strokes. This prevents long underlines, small dots, soft antialiasing, or disconnected strokes from touching the canvas edge or being clipped.
2. Why does the app warn that the signature may be clipped and ask me to enlarge the region?
An important stroke is close to the edge of the region you selected. Return to the signature-region step, expand the selection in the indicated direction, and make sure long underlines, the dot over an English i, and small Chinese strokes are inside the frame. The app stops a potentially clipped export instead of silently cutting the signature.
3. Why is there no camera button?
The current version imports JPG, HEIC, or PNG through the system PhotosPicker or Files. A camera graphic in the home animation illustrates the paper-to-transparent workflow; it is not a tappable camera feature. You can take a photo with the system Camera app and then import it from Photos.
4. Why can’t I import a photo stored in iCloud?
If only an iCloud copy exists, the system must download the original file first. Connect to the network and try again, or download the file to the device and import it through Files. Once the source is available, signature extraction and editing still run on the device.
5. What is the difference between Unlock This Signature and Lifetime Access?
The first source result can be exported for free. Unlock This Signature is a one-time consumable purchase that unlocks the current result for repeated export on this device; Restore Purchases does not promise to move it to another device. Lifetime Access is also a one-time purchase, but it is a non-consumable product that unlocks current and future signatures and can be restored with the Apple Account used for purchase. There is no subscription or automatic renewal. The App Store price is authoritative.
6. Where can I use the transparent PNG?
Insert it as an image in documents, sheets, presentations, PDF editors, form tools, images, or design work that supports transparency, then resize and position it. Use only your own signature or one you are explicitly authorized to use. A PNG does not verify identity or guarantee that a contract or document is legally effective; confirm the recipient’s requirements.
Export and privacy notes
- Save to Photos requests add-only access only when the user chooses it.
- Files access is limited to locations explicitly selected by the user.
- A copied PNG is local to the device and expires after approximately two minutes.
- System sharing uses a protected temporary file that is cleaned after the share interface ends.
- A Photos, Files, mail, or third-party destination chosen by the user may connect, sync, or back up data according to its own settings.
Restore Purchases
Choose Restore Purchases in Settings or on the purchase screen to restore eligible Lifetime Access. The consumable Unlock This Signature product is not transferred to another device through Restore Purchases. If Apple charged the purchase but access did not update, confirm that the device uses the Apple Account used for purchase and send Apple’s transaction information and the app version to support. Do not send an Apple Account password, complete payment details, or an unnecessary signature image.
Contact support
Email: dingronghui@163.com
Suggested subject: Signature PNG Feedback
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