Watermarking

Visible and invisible watermarks

	Visible watermark	Invisible watermark
What it is	Text or a logo placed over the image	A pattern embedded in the image or audio data
Who notices it	Everyone who looks at the file	Only detection software
Main purpose	Discourage use, show status, keep attribution	Trace copies, identify the source, link a file to its records
Effect on the image	Changes what people see	Designed to be imperceptible
Removal	Possible by cropping or retouching	Harder; depending on the method, it survives some compression and resizing

Invisible watermarks are also used to link a file back to its Content Credentials after its embedded metadata has been removed, for example by a platform that strips metadata on upload.

When to use a visible watermark

• Review before licensing. A client or stakeholder chooses images from a shoot before the licence is agreed or the final selection is paid for.
• Pre-release material. Images sent to press or partners under embargo carry "NOT FOR RELEASE" and the release date.
• Portal previews. Visitors to a brand portal may browse an image but must request the clean file.
• Layout drafts. Agencies place library images in drafts before the image is approved for the campaign.
• Traceable distribution. The recipient's name or email address in the watermark shows where a leaked file came from.

A watermark will not stop a determined person, who can crop or retouch it. It does prevent honest mistakes (nobody publishes an image with "NOT FOR RELEASE" across it by accident), and it keeps attribution attached when previews are screenshotted and forwarded.

How a DAM applies watermarks

In a DAM, watermarking is non-destructive. The original file is never altered; the watermark is applied to the previews and downloads served to particular audiences. The same asset can be clean for the brand team, lightly marked for partners and heavily marked for public visitors, without anyone exporting marked copies by hand.

A watermark that works across a whole library follows a few rules:

• Size relative to the image, so it reads the same on a thumbnail and on a 5,000-pixel download.
• Tiled and rotated when it must not be cropped out of the image.
• Low opacity when people still need to judge the image underneath.
• Dynamic text, such as the recipient and the date, when the aim is traceability.
• No clean original for the same audience. If the watermarked preview sits next to an unmarked download, the watermark has no effect.

Watermarking in Freedam

• A watermark designer in the admin area composes watermarks from text and image elements, with settings for position, opacity, blend mode, rotation, tiling and scaling, and previews the result on sample images.
• Watermark text can contain placeholders that are filled in when the file is served: the name or email address of the person downloading, the date, or the asset's title or copyright notice. On a share link limited to listed email addresses, the visitor's email address can be used.
• Access rules apply one watermark to previews and another to downloads, for each audience.
• A share link with a watermark always delivers watermarked downloads, and publication channels that serve images on public URLs can carry one too.
• The original file is never changed. Watermarked copies are generated from the original or a rendition and cached separately.

Frequently asked questions

What is the difference between a watermark and DRM?

A watermark marks the content but does not control what can be done with the file. Digital rights management controls access and use, for example by encrypting the file or limiting who can open it.

Can a watermark be removed?

A visible watermark can be cropped or retouched out, which is why marks that must stay are tiled across the image. Invisible watermarks are harder to remove, and how well they survive editing depends on the method.

Does watermarking reduce image quality?

A visible watermark covers part of the image by design. In a DAM the original is not affected, because the watermark is only added to the copies served to a given audience.