06-07-2012, 10:39 AM
DIGITAL WATERMARKING
DIGITAL WATERMARKING.pptx (Size: 348.8 KB / Downloads: 43)
Introduction
A digital watermark is a digital signal or pattern inserted into a digital document such as text, graphics or multimedia, and carries information unique to the copyright owner, the creator of the document or the authorized consumer.
The term ‘watermark’ was introduced near the end of the 18th century. It was probably given because the marks resemble the effects of water on paper.
Terminologies
Watermarking- as opposed to steganography – in an ideal world can resists attacks. Thus, even if the existence of the hidden information is known, it should be difficult for an attacker to remove the embedded watermark, even if the algorithmic principle is known.
Copy protection- attempts to find ways, which limits the access to copyrighted material and/or inhibit the copy process itself.
Copyright protection- inserts copyright information into the digital object without the loss of quality. Whenever the copyright of a digital object is in question, this information is extracted to identify the rightful owner.
Framewrok
Watermarking is the process that embeds data called ‘watermark’ into a media such that watermark can be detected or extracted later to make an assertion about the media. For example, digital watermarking technique for images is to add a visible seal to the existing image.
Watermarking Types
Visible watermark is a secondary translucent overlaid into the primary image
Invisible watermark is hidden in the content. It can be detected by an authorized agency only.
Public watermark: Such a watermark can be read or retrieved by anyone using the specialized algorithm.
Fragile watermarking technique
A watermark is said to be fragile if the watermark hidden within the host signal is destroyed as soon as the watermarked signal undergoes any manipulation.
When a fragile watermark is present in a signal, we can infer, with a high probability, that the signal has not been altered.
DIGITAL WATERMARKING.pptx (Size: 348.8 KB / Downloads: 43)
Introduction
A digital watermark is a digital signal or pattern inserted into a digital document such as text, graphics or multimedia, and carries information unique to the copyright owner, the creator of the document or the authorized consumer.
The term ‘watermark’ was introduced near the end of the 18th century. It was probably given because the marks resemble the effects of water on paper.
Terminologies
Watermarking- as opposed to steganography – in an ideal world can resists attacks. Thus, even if the existence of the hidden information is known, it should be difficult for an attacker to remove the embedded watermark, even if the algorithmic principle is known.
Copy protection- attempts to find ways, which limits the access to copyrighted material and/or inhibit the copy process itself.
Copyright protection- inserts copyright information into the digital object without the loss of quality. Whenever the copyright of a digital object is in question, this information is extracted to identify the rightful owner.
Framewrok
Watermarking is the process that embeds data called ‘watermark’ into a media such that watermark can be detected or extracted later to make an assertion about the media. For example, digital watermarking technique for images is to add a visible seal to the existing image.
Watermarking Types
Visible watermark is a secondary translucent overlaid into the primary image
Invisible watermark is hidden in the content. It can be detected by an authorized agency only.
Public watermark: Such a watermark can be read or retrieved by anyone using the specialized algorithm.
Fragile watermarking technique
A watermark is said to be fragile if the watermark hidden within the host signal is destroyed as soon as the watermarked signal undergoes any manipulation.
When a fragile watermark is present in a signal, we can infer, with a high probability, that the signal has not been altered.