Multiple watermarks for fidelity assessment
View Patent ↗A system and method of perceptual quality assessment for multimedia content in a communications network employing digital watermarking. A content preparer prepares content for quality assessment by embedding digital watermarks into the multimedia data, each watermark having a different level of robustness with respect to a specified type of potential degradation introduced during content transmission. A quality assessor provides an assessment of the quality of the transmitted content by attempting to detect the presence of at least one watermark, and calculating a quality assessment score based on the level(s) of robustness of the detected watermark(s) with respect to the specified type of potential degradation. The quality assessment score can be calculated based on the level of robustness of the least robust watermark whose presence was successfully detected by the quality assessor. The quality assessor generates an output indication of the transmitted content fidelity using any suitable type of output indication.
1. A method of assessing the perceptual quality of multimedia content provided over a communications channel, comprising the steps of:
incorporating a plurality of digital watermarks in the multimedia content;
transmitting the multimedia content including the plurality of digital watermarks over the communications channel, the plurality of digital watermarks having different levels of robustness with respect to a specified type of degradation in the perceptual quality of the multimedia content introducible during multimedia content transmission;
in a detecting step, detecting at least one of the plurality of digital watermarks in the multimedia content, wherein the detecting step is performed starting with a least robust digital watermark among the plurality of digital watermarks, and, in the event the least robust digital watermark is not detected, continuing with at least one next least robust digital watermark among the plurality of digital watermarks until the at least one of the plurality of digital watermarks is detected; and
in response to having detected the at least one of the plurality of digital watermarks in the multimedia content, generating an output indicative of at least the perceptual quality of the multimedia content based at least in part on the respective level of robustness of the at least one detected digital watermark.
2. The method of claim 1 wherein the at least one detected digital watermark has a lowest level of robustness with respect to the specified type of potential degradation, and wherein the generating of the output includes generating the output indicative of at least the perceptual quality of the multimedia content based at least in part on the lowest level of robustness of the at least one detected digital watermark.
3. The method of claim 2 further comprising:
calculating a quality assessment score based at least in part on the lowest level of robustness of the at least one detected digital watermark, and wherein the generating of the output includes generating the output indicative of at least the perceptual quality of the multimedia content based on the quality assessment score.
4. The method of claim 2 wherein the detecting of the at least one of the plurality of digital watermarks includes making multiple attempts to detect the digital watermarks in the multimedia content, and no longer making the multiple attempts to detect the digital watermarks if the at least one detected digital watermark having the lowest level of robustness is detected.
5. The method of claim 1 wherein the detecting of the at least one of the plurality of digital watermarks includes attempting to detect each of the plurality of digital watermarks in the multimedia content.
6. The method of claim 1 wherein the incorporating of the plurality of digital watermarks in the multimedia content includes incorporating a first plurality of digital watermarks in the multimedia content and incorporating a second plurality of digital watermarks in the multimedia content, first plurality of digital watermarks having different levels of robustness with respect to a specified first type of degradation in the perceptual quality of the multimedia content introducible during multimedia content transmission, and the second plurality of digital watermarks having different levels of robustness with respect to a specified second type of degradation in the perceptual quality of the multimedia content introducible during multimedia content transmission.
7. The method of claim 6 wherein the detecting of the at least one of the plurality of digital watermarks includes detecting at least one of the first plurality of digital watermarks in the multimedia content, and detecting at least one of the second plurality of digital watermarks in the multimedia content.
8. The method of claim 7 wherein a first one of the at least one detected digital watermark from the first plurality of digital watermarks has a lowest level of robustness with respect to the specified first type of potential degradation, wherein a second one of the at least one detected digital watermark from the second plurality of digital watermarks has a lowest level of robustness with respect to the specified second type of potential degradation, and wherein the generating of the output includes generating the output indicative of at least the perceptual quality of the multimedia content based at least in part on one or more of the lowest level of robustness of the first one of the at least one detected digital watermark from the first plurality of digital watermarks and the lowest level of robustness of the second one of the at least one detected digital watermark from the second plurality of digital watermarks.
9. The method of claim 8 further comprising:
calculating a quality assessment score based at least in part on the lowest level of robustness with respect to the specified first type of potential degradation and the lowest level of robustness with respect to the specified second type of potential degradation, and wherein the generating of the output includes generating the output indicative of at least the perceptual quality of the multimedia content based on the quality assessment score.
10. The method of claim 8 wherein the detecting of the at least one of the plurality of digital watermarks includes making multiple attempts to detect the digital watermarks from the first plurality of digital watermarks in the multimedia content, and no longer making the multiple attempts to detect the digital watermarks from the first plurality of digital watermarks if the first one of the at least one detected digital watermark from the first plurality of digital watermarks having the lowest level of robustness is detected.
11. The method of claim 8 wherein the detecting of the at least one of the plurality of digital watermarks includes making multiple attempts to detect the digital watermarks from the second plurality of digital watermarks in the multimedia content, and no longer making the multiple attempts to detect the digital watermarks from the second plurality of digital watermarks if the second one of the at least one detected digital watermark from the second plurality of digital watermarks having the lowest level of robustness is detected.
12. The method of claim 7 wherein the detecting of the at least one of the plurality of digital watermarks includes attempting to detect each of the first plurality of digital watermarks in the multimedia content, and attempting to detect each of the second plurality of digital watermarks in the multimedia content.
13. The method of claim 1 wherein the detecting of the at least one of the plurality of digital watermarks in the multimedia content includes generating at least one binary-value output indicative of detection of a presence or an absence of the at least one of the plurality of digital watermarks in the multimedia content.
14. The method of claim 1 wherein the detecting of the at least one of the plurality of digital watermarks in the multimedia content includes generating at least one continuous certainty-value output indicative of a likelihood of detection of a presence of the at least one of the plurality of digital watermarks in the multimedia content.
15. The method of claim 14 wherein the generating of the output indicative of at least the perceptual quality of the multimedia content includes generating the output indicative of at least the perceptual quality of the multimedia content based on a specified function of some or all of the at least one continuous certainty-value output.
16. A system for assessing the perceptual quality of multimedia content provided over a communications channel, comprising:
a multimedia content preparer including at least one digital watermark embedder, the at least one digital watermark embedder being operative to incorporate a plurality of digital watermarks in the multimedia content, the plurality of digital watermarks having different levels of robustness with respect to a specified type of degradation in the perceptual quality of the multimedia content introducible during multimedia content transmission; and
a multimedia content quality assessor including at least one digital watermark detector and a multimedia quality assessment module, the at least one digital watermark detector being operative to detect at least one of the plurality of digital watermarks in the multimedia content, starting with a least robust digital watermark among the plurality of digital watermarks, and, in the event the least robust digital watermark is not detected, continuing with at least one next least robust digital watermark among the plurality of digital watermarks until the at least one of the plurality of digital watermarks is detected, and the multimedia quality assessment module being operative, in response to the at least one digital watermark detector having detected the at least one of the plurality of digital watermarks in the multimedia content, to generate an output indicative of at least the perceptual quality of the multimedia content based at least in part on the respective level of robustness of the at least one detected digital watermark.
17. The system of claim 16 wherein the detected digital watermark has a lowest level of robustness with respect to the specified type of potential degradation, and wherein the multimedia quality assessment module is further operative to generate the output indicative of at least the perceptual quality of the multimedia content based at least in part on the lowest level of robustness of the at least one detected digital watermark.
18. The system of claim 17 wherein the multimedia quality assessment module is further operative to calculate a quality assessment score based at least in part on the lowest level of robustness with respect to the specified type of potential degradation, and to generate the output indicative of at least the perceptual quality of the multimedia content based on the quality assessment score.
19. The system of claim 17 wherein the at least one digital watermark detector is further operative to make multiple attempts to detect the digital watermarks in the multimedia content, and to no longer make the multiple attempts to detect the digital watermarks if the at least one detected digital watermark having the lowest level of robustness is detected.
20. The system of claim 16 wherein the at least one digital watermark detector is further operative to attempt to detect each of the plurality of digital watermarks in the multimedia content.
21. The system of claim 16 wherein the at least one digital watermark embedder comprises a plurality of digital watermark embedders, one or more of the plurality of digital watermark embedders being operative to incorporate a respective one or more of the plurality of digital watermarks in the multimedia content.
22. The system of claim 16 wherein the multimedia content preparer further includes at least one digital watermark generator operative to generate at least one of the plurality of digital watermarks.
23. The system of claim 22 wherein the at least one digital watermark generator is further operative to generate at least one of the plurality of digital watermarks based at least in part on data from the multimedia content.
24. The system of claim 16 wherein the at least one digital watermark detector is further operative to generate at least one binary-value output indicative of detection of a presence or an absence of the at least one of the plurality of digital watermarks in the multimedia content.
25. The system of claim 16 wherein the at least one digital watermark detector is further operative to generate at least one continuous certainty-value output indicative of a likelihood of detection of a presence of the at least one of the plurality of digital watermarks in the multimedia content.
26. The system of claim 25 wherein the multimedia quality assessment module is further operative to generate the output indicative of at least the perceptual quality of the multimedia content based on a specified function of some or all of the at least one continuous certainty-value output.