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US 5,809,160 AGranted
Method for encoding auxiliary data within a source signal
AssigneeDigimarc Corporation
InventorsRobert D. Powell, Mark J. Nitzberg
Life of this patent
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AssigneeDigimarc Corporation
InventorsRobert D. Powell, Mark J. Nitzberg
Estimating the term…
A method and system for embedding signatures within visual images in both digital representation and print or film. A signature is inseparably embedded within the visible image, the signature persisting through image transforms that include resizing as well as conversion to print or film and back to digital form. Signature points are selected from among the pixels of an original image. The pixel values of the signature points and surrounding pixels are adjusted by an amount detectable by a digital scanner. The adjusted signature points form a digital signature which is stored for future identification of subject images derived from the image. In one embodiment, a signature is embedded within an image by locating relative extrema in the continuous space of pixel values and selecting the signature points from among the extrema. Preferably, the signature is redundantly embedded in the image such that any of the redundant representations can be used to identify the signature. Identification of a subject image includes ensuring that the subject image is normalized with respect to the original image or the signed image. Preferably, the normalized subject image is compared with the stored digital signature.
A method of encoding N-bits of auxiliary data within a source signal, N being at least one, the source signal being comprised of samples, each having a binary value, the method including:
A method of encoding N-bits of auxiliary data within a source signal, N being at least one, the source signal being comprised of samples, each having a binary value, the method including, for each bit of the auxiliary data:
In a method of encoding N-bits of auxiliary data within a source signal, N being at least one, the source signal being comprised of samples, each having a binary value, the method including--for each bit of the auxiliary data--changing the value of a source signal sample in accordance therewith, an improvement comprising employing a random function to randomize the locations within the source signal at which said bits of auxiliary data change said values of the source signal samples.
A method of encoding N-bits of auxiliary data within a source signal, N being at least one, the source signal representing image data, the method including:
A method of encoding N-bits of auxiliary data within a source signal, N being at least one, the source signal representing image data, the method including:
A method of encoding N-bits of auxiliary data within a source signal, N being at least two, the source signal representing an image and including plural pixels,
In a method of marking an image to encode auxiliary data therein, the method including changing the image at plural points thereof, an improvement comprising defining a bounding area within which certain changes to the image are to be confined, said bounding area being less than the entirety of the image, and only making said certain changes within said area.
In a method of marking an image to encode auxiliary data therein, the method including changing the image at plural points thereof, an improvement wherein the image is comprised of pixels, and the method includes randomly selecting pixels where changes are to be made.
In a method of marking an image to encode auxiliary data therein, the method including changing the image at plural points thereof, an improvement wherein the image is comprised of pixels, the changes increase or decrease a value of a signature pixel at each said point, and the method further includes increasing or decreasing the value of each pixel adjoining said signature pixels to correspond to the change of the signature pixel adjacent thereto.
A method of marking an image to encode auxiliary data therein, said data facilitating later identification of said image, the method comprising:
Dependencies are inferred from the claim text.