Object edge watermarking
First Claim
1. A method of imperceptibly embedding auxiliary data into an image signal comprising:
- detecting an object edge in the image signal;
forming a connected edge;
creating a message signal to be embedded into the connected edge;
modifying pixel values along the connected edge to encode the message signal such that the message signal is substantially imperceptible in the image signal when viewed.
1 Assignment
0 Petitions
Accused Products
Abstract
The disclosure provides a method of imperceptibly embedding auxiliary information along object edges in image signals. It also provides a method of decoding this auxiliary information from image signals.
The object edge digital watermarking method may be used in combination with digital watermarking techniques that encode auxiliary data across image regions, such as image blocks. For example, a digital watermark embedder may be programmed to adapt its embedding technique based on the attributes of the image signal. For parts of an image that have strong edges surrounded by smooth regions, the object edge embedding technique is used, while in other parts that have high a degree of signal activity (e.g., busyness or texture), a region based encoding technique that takes advantage of the masking properties of high signal activity is used.
-
Citations
13 Claims
-
1. A method of imperceptibly embedding auxiliary data into an image signal comprising:
-
detecting an object edge in the image signal;
forming a connected edge;
creating a message signal to be embedded into the connected edge;
modifying pixel values along the connected edge to encode the message signal such that the message signal is substantially imperceptible in the image signal when viewed. - View Dependent Claims (2, 3, 4, 5, 7)
-
-
6. A computer readable medium on which is stored software for performing a method comprising:
-
detecting an object edge in the image signal;
evaluating pixel values along the edge to detect presence of a hidden index;
using the index to detect a variable message hidden at a predetermined spatial location relative to the edge; and
decoding the variable message from pixel values at the predetermined spatial location relative to the edge.
-
-
8. A method of decoding auxiliary data that has been imperceptibly embedded into an image signal comprising:
-
detecting an object edge in the image signal;
forming a connected edge;
evaluating pixel values along the connected edge to detect presence of the auxiliary data; and
decoding the auxiliary data from the pixel values along the connected edge. - View Dependent Claims (9, 10, 11, 12, 13)
-
Specification