Image analysis – Applications
Reexamination Certificate
2001-10-26
2003-02-11
Patel, Jayanti K. (Department: 2623)
Image analysis
Applications
C348S460000
Reexamination Certificate
active
06519351
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for recording and reproducing image data, particularly electronic watermark information embedded (hidden) in video signals, which is used for the picture recording and reproduction control or for marking the origins of the records, and also relates to a recording medium on which electronic watermark information is recorded by being embedded in a video signal.
2. Description of the Prior Art
Among the several schemes proposed for embedding electronic watermark information in video signals, representative one is described in the article entitled “Data Hiding Technique” in publication ITE Technical Report, Vol.21, No.31, pp.3-8. Another conventional information embedding technique is described in publication Nikkei Electronics, No.683, pp.99-107, published in 1997. These conventional techniques are intended to embed, in a video signal, information that is different in terms of statistical characteristics of image from the inherent picture information carried by the video signal, and use the embedded information at the time of picture reproduction for identifying the origin of the record or producing a control signal which enables or disable the reproducing of the video signal.
However, these publications mainly describe recording means and do not describe the details of means of detecting electronic watermark information at the time of reproducing. Electronic watermark information recorded by a VCR or optical disk unit has its reproduced signal level varied depending on the reproduction characteristics of these apparatus. The reproduced signal waveform of the electronic watermark information varies also depending on the frequency characteristics of these apparatus.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method and apparatus for recording and reproducing electronic watermark information and a recording medium which enable easy detection of the watermark information at the time of reproducing.
Another object of the present invention is to provide a method and apparatus for recording and reproducing electronic watermark information and a recording medium which enable easy reproduction of the embedded electronic watermark information even if the reproduction characteristics of the reproduction apparatus vary.
Still another object of the present invention is to provide a method and apparatus for recording and reproducing electronic watermark information and a recording medium which enable easy reproduction of the electronic watermark information even if the signal level of the watermark information varies.
Still another object of the present invention is to provide a circuit arrangement which is scarcely affected by the reproduction level and frequency characteristics of the recording apparatus in detecting electronic watermark information included in a video signal which has been recorded by the recording apparatus.
In order to achieve the above objectives, the recording medium based on this invention is designed to record a video signal, electronic watermark information which is embedded in the video signal and a reference signal which is inserted at a position different from the position of the watermark information in the video signal.
The inventive method of recording electronic watermark information includes the operational steps of embedding electronic watermark information in a video signal at a minimal disturbance against the video signal, and recording a reference signal which is inserted at a position different from the position of the watermark information in the video signal.
The inventive method of recording and reproducing electronic watermark information includes the operational steps of recording electronic watermark information which is embedded in a video signal at a minimal disturbance against the video signal and a reference signal which is inserted at a position different from the position of the watermark information, reproducing the reference signal, and modifying the watermark information based on the reference signal.
The inventive method of recording electronic watermark information includes the operational steps of calculating the visually-permissible alteration range of luminous value of the luminance signal included in a video signal, and altering the luminous value of the luminance signal at a predetermined position within the calculated alteration range.
The inventive method of recording electronic watermark information includes the operational steps of calculating the visually-permissible alteration range of luminous value of the luminance signal included in a video signal, and altering the luminous value of the luminance signal at a predetermined position in case the altered luminous value is within the calculated alteration range.
The inventive method of reproducing electronic watermark information includes the operational steps of detecting a reference signal for detecting electronic watermark information from a recording medium on which are recorded a video signal, the watermark information which is embedded in the video signal at a minimal disturbance against the video signal and the reference signal which is inserted at a position different from the position of the watermark information, and modifying the watermark information based on the reference signal.
The inventive method of reproducing electronic watermark information includes the operational steps of detecting a reference signal for reproducing electronic watermark information from a recording medium on which are recorded a video signal, the watermark information which is embedded in the video signal based on the alteration of luminous value of the luminance signal included in the video signal and the reference signal which is inserted at a position different from the position of the watermark information, and modifying the luminous value of the watermark information based on the reference signal.
The inventive method of recording and reproducing electronic watermark information includes the operational steps of recording a video signal, electronic watermark information which is embedded in the video signal at a minimal disturbance against the video signal and a reference signal which is inserted at a position different from the position of the watermark information, and detecting the watermark information based on the reference signal. The inventive method of recording electronic watermark information includes the operational steps of recording a video signal, electronic watermark information which is embedded in the video signal at a minimal disturbance against the video signal and a reference signal which is inserted at a position different from the position of the watermark information.
The inventive method of reproducing electronic watermark information includes the operational steps of detecting electronic watermark information based on a reference signal thereby to reproduce the watermark information from a recording medium on which are recorded a video signal, the watermark information which is embedded in the video signal at a minimal disturbance against the video signal and the reference signal which is inserted at a position different from the position of the watermark information.
The inventive apparatus for recording electronic watermark information comprises a detection circuit which calculates the permissible alteration range of luminous value depending on the luminous value of the luminance signal included in a video signal, and a watermark information embedment processing circuit which embeds electronic watermark information in the video signal by altering the luminous value of the luminance signal at a predetermined position within the calculated alteration range.
The inventive apparatus for recording electronic watermark information comprises a detection circuit which calculates the permissible alteration range of luminous value depending on the luminous value of the luminance signal included in a video signal, and a waterma
Arai Takao
Kimura Hiroyuki
Takeuchi Toshifumi
Yoshiura Hiroshi
Antonelli Terry Stout & Kraus LLP
Hitachi , Ltd.
Patel Jayanti K.
LandOfFree
Method and apparatus for recording and reproducing... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for recording and reproducing..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for recording and reproducing... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3119656