Remove PDF file watermarks. Watermark in PDF document

iSkysoft PDF Editor 6 Professional for Mac allows you to add, edit, and remove watermarks in PDF documents.

1 Adding a watermark to PDF

After you open the PDF file, open the "Edit" menu and select "Watermark" (Watermark). Use the “Add” option, after which you will see the “Add Watermark” panel on the right side of the program window.

Adding a Watermark as Text to PDF: Use the “Add Watermark” panel and select the “Text” option, then enter the text you want. You can customize the font, color and size of your watermark.

Adding an Image Watermark to PDF: Select the "Image" image option, then select the file on your computer to be used as the watermark.

Add Watermark as PDF: Select the “PDF” option and enter the page number to be used as a watermark for your file.

Once you've decided on a watermark, you can use the Appearance tab to define the location, transparency, and other watermark options.

After that go to the “Position” tab to define the position of the watermark in your PDF file.

After completing the customization process, you can see how it will look in your PDF document, then click the “Add” button to save the watermark.

2 Remove watermark from PDF

To remove watermarks from a PDF file, select “Watermark” from the “Edit” menu, then click the “Remove” button. You will see a pop-up window asking if you want to remove the watermark. Click “Yes” to remove the watermark.

3 Batch add or remove watermark to PDF

iSkysoft PDF Editor 6 Professional for Mac allows you to add and remove watermarks to multiple PDF files at once.

Open the main page of the program and click on the “Batch Process” tab. Then select "Add" or "Remove" option. Click the “Add Files…” button to import PDF files. After that, you can use the steps above to add or remove watermarks to PDF.

A watermark is text or an image placed behind or before the content of a document. It is usually information that identifies the author of the document.
For watermarks, you can adjust the size, font, style, color, location on the page, specify the page numbers on which they will be displayed, etc., and also select an image from a PDF file as a watermark. Watermarks of different types can be used in one file. You can add multiple watermarks to each page of a document.
Watermark settings can be saved for later use.

Adding watermarks.

To add watermarks to a PDF document, select from the main menu: Document>Watermark>Add

• View Setting the parameters of the inserted image.
  Turn- The value of the rotation angle (in degrees) of the watermark in relation to the document page.
  Opacity- Opacity value (in percent).
  Scale relative to target page - The scale of the watermark in relation to the page of the document on which this mark will be added.

• Source Document Select the type of watermark to be inserted. This can be entered text or an image from a PDF file.
  Text When the marker is set, the source material for the watermark will be the entered text.
  Font- Set the following options for the watermark text: font type, size, color, and text highlighting with underlining.

• Saved settings List of saved watermark templates.
  To add a template, specify the required watermark options and click Save. In the dialog box that appears, write down the name of the template.
  To delete a template, select it from the list of saved settings. Confirm the deletion of the template in the dialog box that appears.

• File When the marker is set, the source material for the watermark will be an image loaded from a PDF or image file.
  Overview- Select source PDF file or image file for watermark.
  Page number- The page number of the file whose image will be used as a watermark. (The total number of pages in the file is displayed under Total Pages)
  Scale- The scale of the watermark in relation to the original image inserted from the PDF file. To make this item active, remove the marker in the item View> Scale relative landing page.

• Position Sets the position of the watermark on the document page.
  Vertical shift- The value of the vertical offset of the watermark relative to the selected position: Top, Center or Bottom.
  Horizontal shift- The value of the horizontal offset of the watermark relative to the selected position: Top, Center or Bottom.
  Units- Choice of units of measurement for specifying the shift distance.

• Page Range Specify the page range to add watermarks.

Remove all watermarks.

To delete single characters, select from the main menu Document>Watermark>Delete.All single characters in the document will be removed.

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For image-based watermarks, there are several tools that promise to remove them automatically. For instance:

You can try all of these, but a license is required to get the desired result.

However, the watermark of this particular PDF file (which emailed me) is not a single image that is repeated on all pages. As it turns out, PDFCreator hardcoded it (nearly pixel by pixel) into each of them. This makes the watermark much harder to remove (and results in a rather bloated PDF).

Since the watermark is actually made up of many small images, you can remove them with a PDF editor (such as Foxit Advanced PDF Editor) by simply selecting them and clicking Remove. Unfortunately, you have to repeat this for every page.

A less time-consuming solution would be to programmatically remove watermarks. We need:

• Pdftk: A tool for (un)compressing and fixing PDF streams.
• Notepad++: A text editor capable of replacing Perl's supported regular expressions.

Actions

Download Pdftk and extract pdftk.exe and libiconv2.dll v %windir%\System32, a directory on the way, or any other location of your choice.

Download and install Notepad++.

PDF streams are usually compressed using the DEFLATE algorithm. This saves space but makes the PDF source illegible.

pdftk original.pdf output uncompressed.pdf uncompress

unpacks all streams so they can be modified with a text editor.

open uncompressed.pdf using Notepad++ to show the watermark structure.

In this particular case, each page starts with a block

Q 9 0 0 9 2997 4118.67 cm BI /CS/RGB /W 1 /H 1 /BPC 8 ID Ÿ®¼ EI Q

and almost 4000 blocks like this one. This particular block sets only one (/W 1 /H 1) watermark pixels.

Scrolling down to the pattern change shows that the watermark stream is 95,906 bytes (counting newlines). The exact flow is repeated on every page of the PDF file.

Press Ctrl + H and install the following:

Find: q 9 0 0 9 2997 4118\.67 cm.(95881) Replace: (blank) Match case: checked Wrap around: checked Regular expression: selected . matches newline: checked

The regular expression q 9 0 0 9 2997 4118\.67 cm.(95881) matches the first line of the above block (q 9 0 0 9 2997 4118.67 cm) and all subsequent 95,881 characters, i.e. the watermark stream.

Clicking Replace All, remove it from all pages of the PDF file.

Now the watermark is removed, but the PDF file has errors (the length of the streams is incorrect) and it is uncompressed.

pdftk uncompressed.pdf output nowatermark.pdf compress

takes care of everyone.

uncompressed.pdf no longer required. You can remove it.

The result is the same PDF without the watermark (and about half the size).

All of these can be tried for free, but a license is required to get the desired result.

However, the watermark of this particular PDF file (which the OP emailed me) is not a single image that is repeated on all pages. As it turns out, PDFCreator hardcoded it (nearly pixel by pixel) into each of them. This makes it much more difficult to remove the watermark (and results in a rather bloated PDF file).

Since the watermark is actually made up of many tiny images, you can remove them with a PDF editor (such as Foxit Advanced PDF Editor) by simply selecting them and clicking Remove. Unfortunately, you have to repeat this for every page.

A less time-consuming solution would be to remove the watermark programmatically. We need:

• Pdftk: A tool for (un)compressing and fixing PDF streams.
• Notepad++ : A text editor capable of replacing Perl compatible regular expressions.

measures

Download Pdftk and extract pdftk.exe and libiconv2.dll v %windir%\System32, a directory along the path, or any other location of your choice.

Download and install Notepad++.

PDF streams are usually compressed using the DEFLATE algorithm. This saves space but makes the PDF source illegible.

pdftk original.pdf output uncompressed.pdf uncompress

unpacks all streams so they can be modified by a text editor.

open uncompressed.pdf using Notepad++ to reveal the watermark structure.

In this particular case, each page starts with a block

Q 9 0 0 9 2997 4118.67 cm BI /CS/RGB /W 1 /H 1 /BPC 8 ID Ÿ®¼ EI Q

and almost 4000 blocks like this one. This particular block sets only one (/W 1 /H 1) watermark pixels.

Scrolling down to the pattern change shows that the watermark stream is 95,906 bytes long (counting newlines). The exact same flow is repeated on every page of the PDF file.

Press Ctrl + H and install the following:

Find: q 9 0 0 9 2997 4118\.67 cm.(95881) Replace: (blank) Match case: checked Wrap around: checked Regular expression: selected . matches newline: checked

The regular expression q 9 0 0 9 2997 4118\.67 cm.(95881) matches the first line of the above block (q 9 0 0 9 2997 4118.67 cm) and all subsequent 95,881 characters, i.e. the watermark stream.

Pressing " Replace all" removes it from all pages of the PDF file.

The watermark is now removed, but the PDF file has errors (the length of the streams is incorrect) and is not compressed.

pdftk uncompressed.pdf output nowatermark.pdf compress

takes care of both.

uncompressed.pdf is no longer needed. You can remove it.

The result is the same PDF without the watermark (and about half the size).