Perceptual modeling of media signals based on local contrast and directional edges
First Claim
1. A method of reducing human perceptibility of visible artifacts attributable to embedding a digital watermark in a media signal, said method comprising:
- determining a contrast measurement for at least some local areas of the media signal;
adjusting a contrast measurement for a local area if the contrast measurement is above a predetermined level; and
embedding the digital watermark in the at least some local areas in a manner determined at least in part by their respective contrast measurement.
6 Assignments
0 Petitions
Accused Products
Abstract
A perceptual model performs an analysis of a media signal, such as an image or audio signal. The model may be used in media signal processing applications such as digital watermarking and data compression to reduce perceptibility of changes made to code the signal. In one implementation, a method of reducing human perceptibility of visible artifacts attributable to embedding a digital watermark in a media signal is provided. The method determines a contrast measurement for local areas of the media signal; adjusts a contrast measurement for a local area if the contrast measurement is above a predetermined level; and embeds the digital watermark in the local areas in a manner determined at least in part by their respective contrast measurement.
-
Citations
20 Claims
-
1. A method of reducing human perceptibility of visible artifacts attributable to embedding a digital watermark in a media signal, said method comprising:
-
determining a contrast measurement for at least some local areas of the media signal;
adjusting a contrast measurement for a local area if the contrast measurement is above a predetermined level; and
embedding the digital watermark in the at least some local areas in a manner determined at least in part by their respective contrast measurement. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method of reducing the human perceptibility of visible artifacts attributable to embedding a digital watermark in a media signal, said method comprising:
-
determining a contrast measurement for local areas of the media signal;
adjusting a contrast measurement for a local area if the contrast measurement is above a predetermined level;
analyzing the media signal to compute a measure of directional edges in the signal; and
embedding the digital watermark in the local areas as determined at least in part by their respective contrast measurement and measure of directional edges. - View Dependent Claims (13, 14, 15)
-
-
16. Apparatus comprising:
-
electronic processing circuitry;
memory in communication with the electronic processing circuitry, said memory including executable instructions stored thereon, said instructions being executed by said electronic processing circuitry, said instructions comprising instructions to;
analyze a media signal to;
i) determine a measure of directional edges at samples in the media signal;
ii) measure local contrast at samples in the media signal;
iii) map local contrast to a measure of sensitivity;
use data representing the measure of directional edges and the measure of sensitivity to compute control data; and
adjust steganographic embedding of the media signal according to the control data in a manner that minimizes perceptibility of the embedding. - View Dependent Claims (17, 18, 19, 20)
-
Specification