Digital watermark - Revision history

Parchivist: /* Software */

2023-10-29T22:25:51Z

‎Software

Parchivist at 13:00, 2 September 2023

2023-09-02T13:00:03Z

Parchivist at 16:55, 31 August 2023

2023-08-31T16:55:20Z

Jsummers: /* See also */

2017-06-15T16:55:16Z

‎See also

Jsummers at 16:28, 15 June 2017

2017-06-15T16:28:55Z

Jsummers: Created page with "{{FormatInfo |formattype=electronic |subcat=Security }} A '''digital watermark''' is a kind of digital signature, usually in the form of a subtle modification to the main cont..."

2017-06-15T15:19:09Z

Created page with "{{FormatInfo |formattype=electronic |subcat=Security }} A '''digital watermark''' is a kind of digital signature, usually in the form of a subtle modification to the main cont..."

New page

{{FormatInfo
|formattype=electronic
|subcat=Security
}}
A '''digital watermark''' is a kind of digital signature, usually in the form of a subtle modification to the main content of an image, audio, or video file. To put it another way, a digital watermark stores [[metadata]] ''inside'' the main content of a file, instead of separately. There are many different reasons for using a watermark, but the main point is to make it difficult to remove the metadata.

A digital watermark could be anything from a clearly visible overlayed semi-transparent copyright notice, to a [[Steganography|steganographic]] technique that makes the signature virtually undetectable, or anything in between. It could be a simple notice of what software created the file, or it could contain detailed tracking information intended to help figure out who created the file.

Calling something a "watermark" usually implies that it is designed to survive at least minor modifications to the document.

Similar to [[bar codes]], some kinds of watermarks store digital data in physical documents. See [[Watermark (physical)]].

== See also ==
* [[Watermark (physical)]]

== Links ==
* [[Wikipedia: Digital watermarking]]

[[Category:Elements of File Formats]]
[[Category:Forensics and Law Enforcement]]
[[Category:Metadata]]

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 == Software ==
 * [[docx steganography]]
 * [[ooxml Steg]]
 * [[OpenStego]]

@@ Line 7: / Line 7: @@
 A digital watermark could be anything from a clearly visible overlayed semi-transparent copyright notice, to a [[Steganography|steganographic]] technique that makes the signature virtually undetectable, or anything in between. It could be a simple notice of what software created the file, or it could contain detailed tracking information intended to help figure out who created the file.
-Calling something a "watermark" usually implies that it is designed to survive at least minor modifications to the document. Indeed the major difference between steganography and watermarking is that steganography is focused on packing as much data into a file as possible at the cost of robustness while watermarking puts just enough data to ID the author/file but tries to be robust enough that format conversions, resizing, cropping, etc don't impact the ability to read that data.
+There are 2 main features that separate a watermark from general steganography
 Similar to [[bar codes]], some kinds of watermarks store digital data in physical/analog documents. See [[Watermark (physical)]].
 == Software ==
 * [[OpenStego]]
 * [[wbStego]] - has a minor PDF watermarking function
 == See also ==

← Older revision		Revision as of 16:55, 15 June 2017
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	== See also ==		== See also ==
		+	* [[Digital Rights Management]]
	* [[Watermark (physical)]]		* [[Watermark (physical)]]

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 |subcat=Security
 }}
-A '''digital watermark''' is a kind of digital signature, usually in the form of a subtle modification to the main content of an image, audio, or video file. To put it another way, a digital watermark stores [[metadata]] ''inside'' the main content of a file, instead of separately. There are many different reasons for using a watermark, but the main point is to make it difficult to remove the metadata.
+A '''digital watermark''' is a kind of digital signature, usually in the form of a subtle modification to the main content of an image, audio, or video file. To put it another way, a digital watermark stores [[metadata]] ''inside'' the main content of a file, instead of separately. There are a number of different reasons for using a watermark, but the main point is to make it difficult to remove the metadata.
 A digital watermark could be anything from a clearly visible overlayed semi-transparent copyright notice, to a [[Steganography|steganographic]] technique that makes the signature virtually undetectable, or anything in between. It could be a simple notice of what software created the file, or it could contain detailed tracking information intended to help figure out who created the file.
@@ Line 9: / Line 9: @@
 Calling something a "watermark" usually implies that it is designed to survive at least minor modifications to the document.
-Similar to [[bar codes]], some kinds of watermarks store digital data in physical documents. See [[Watermark (physical)]].
+Similar to [[bar codes]], some kinds of watermarks store digital data in physical/analog documents. See [[Watermark (physical)]].
 == See also ==