OmniDocHow to sign a scanned PDF, directly stamp the image signature on it
The text of the scanned PDF cannot be changed directly, but the signature image can be placed on the corresponding page. This article explains how to determine the file type, prepare a signature image, place the signature and export it, and how to check each item after signing.
Key points of this article
- First try to select a piece of text. If you cannot select it, it will usually be a scanned copy. The signature should be completed by "putting a picture" instead of changing the text.
- Try to write the signature image by hand on white paper and then take a photo or scan it. Cut off the excess white edges. The background should be clean and the signature strokes should be clear.
- Place the signature in the signature field in the PDF editor, drag it into place and resize it, and check page by page whether all the places that should be signed are signed.
- Export as a new file and keep the original. After signing, check the number of pages, signature position and clarity before sending it to the other party.
Many people receive a scanned version of a contract, stamped document or certification document and need to sign it before sending it back, only to find that the text in the document cannot be clicked or changed. Most people who search for issues such as how to make a scanned signature using a pdf signature have encountered this situation: the file is not editable text, but page pictures.
This kind of document does not require "changing the text", just put the signature as an image in the correct position on the page. This article is written for people who need to sign on scanned documents. After reading it, you can determine the file type, prepare a signature image, use a desktop client to complete the signature and export it, and check the signed results item by item.
How to sign the scanned PDF? One sentence conclusion
The content of the scan is an image, and the signature can also be superimposed in the form of an image. The key is to first determine which type of file you have and then choose the right method.
| your situation | Recommended practices | reason |
|---|---|---|
| The document is a scanned copy and only needs to be signed or stamped. | Prepare a signature picture and put it in the signature column | No need to change the original text, the pictures can be superimposed directly |
| The document is a scanned copy and the text in it needs to be changed. | First do OCR recognition, then edit the paragraph text, and finally sign | Only when the text layer is recognized can the paragraph content be changed. |
| The document is an electronic version with optional Chinese characters | Sign directly with the PDF editor, or change the text in the editor and then sign | The text can be modified directly, and the signature position is better aligned. |
| The signer is not around and the other party needs to sign online | Send PDF to sign via online signing request | The other party does not need to install software, and can send it back after signing. |
Before you start: Confirm these points first
Knowing these three things before taking action will save you a lot of detours.
First, confirm whether the document is a scanned copy. Open the PDF and try to select a piece of text with your mouse. If you cannot select it, or if you select a picture of the entire page, it is a scanned copy. This determines whether you need OCR later, and whether you can directly change the text.
Second, confirm the signature location and page number. Contracts often require signatures on the first page, last page or seam, and sometimes every page must be signed. List the page numbers that need to be signed first to avoid discovering that a page is missing after signing.
Third, confirm whether the other party has any requirements for the signature form. Some scenarios require handwritten signatures, while others accept picture signatures or electronic signatures. Before signing a contract, ask the other party whether they accept picture signatures. The effectiveness depends on the specific scenario and the other party's requirements. This article does not make a judgment on this.
Fourth, prepare a clean signature image. Write your signature by hand on white paper, take a photo with your phone in a well-lit area, or scan it with a scanner. Cut off the excess white edges so that the signature fills the screen as much as possible and the strokes remain clear. The cleaner the background, the more natural it will look when superimposed on the page.
Steps to add image signature to scanned PDF in desktop client
The following steps apply to the OmniDoc desktop client (available for download at download.omnidoc.top for Windows, macOS, and Linux).
- Download and open the client: Install the OmniDoc desktop client and enter the PDF editor after starting it.
- Import scans: Import the scanned PDF that needs to be signed into the editor, browse it page by page, and confirm that the page number and content are correct.
- Find the signature function: Select the signature function in the PDF editor and use a signature image as the signature content instead of drawing directly on the screen with the mouse.
- Import signature image: Select the signature image you prepared in advance and confirm that it is clearly visible in the preview.
- Place it in the signature field: Drag the signature to the corresponding signature field or signature area, and align it with the horizontal line or signature box.
- Resize: Drag the corners of the signature to scale it so that the size is basically consistent with other signatures in the document to avoid being too large and covering the text.
- Page by page: If multiple pages of signatures are required, complete them page by page according to the page numbers listed previously, checking each page.
- Export as new file: Save or export as a new PDF file. The file name can be marked with "signed" and the original document will remain unchanged.
If there is text in the scan that needs to be modified, you can use OCR to identify it before signing, so that the text can be selected and edited, and then modify the paragraph text. The recognition results of OCR require manual verification, especially numbers, dates and amounts.
Check each item after completion
After exporting, don’t rush to send it out, check it item by item.
| Check items | How to see | What to do if there is a problem |
|---|---|---|
| Is the signature clear? | Zoom in to the actual display scale to view the strokes and edges of the signature | Change the signature picture more clearly and reposition it. |
| Whether the signature location is correct | Check the signature bar and the horizontal line to see if it is pressed against the text. | Drag the signature or zoom out, undo it and redo it if necessary |
| Is the number of pages complete? | Look through the pages one by one and compare the list of page numbers listed above | Make up the missing page and re-export it. |
| Is the original text intact? | Compare key paragraphs, numbers, and dates before and after signature | If you correct it by mistake, go back to the original and re-operate, do not cover the original directly |
| Whether the format meets the requirements of the other party | Check the file format and signature form specified by the other party | Adjust according to the other party's request and then send it. |
# which method is suitable for you?
If you sign your own document, just import the signed picture, put it in place, and export it. The whole process is usually done at once. If you need more than one person to sign, or if the other party is out of town, it is more suitable to initiate an online signature request, allowing the other party to sign directly on the web page, saving the trouble of sending documents back and forth.
If the document still needs to modify the content, such as filling in the date and correcting the wrong words, it is recommended to modify the content first, check it correctly before signing, and do not reverse the order, otherwise the signature will be inconsistent with the content.
# frequently asked questions (FAQ)
1. Can you change the text after the scanned piece is signed?
The signature is just a picture superimposed on the page and will not change the original image content. If you need to change the text, first use OCR to identify the text layer, and then edit the paragraph text, modify and then sign.
2. The background of the signature picture is white. What if the cover is very conspicuous?
You can first use general image processing software to remove the white background, or when re-shooting, let the signature fall on the solid color, uniform light on the paper. The cleaner the background, the more natural it will be after stacking.
3. If the other party is not around, how can I get him to sign?
The PDF can be sent to the other party through the signature request function of OmniDoc, and the other party can sign it online and send it back, without having to mail or repeatedly transmit documents back and forth.
4. Must the picture signature have legal effect?
Effectiveness depends on the specific scenario, the applicable rules and the agreement between the two parties, and cannot be generalized. Try to ask the other party and relevant institutions whether they accept picture signatures or electronic signatures before signing the contract.
# Summary
The core of scanning PDF signature is: first confirm the file type, then prepare a clean signature picture, put it on the corresponding page and check it page by page, and finally export to retain the original for the new file. If you do it in this order, the scanned pieces can also be successfully signed.
