Abstract: The present invention provides methods and apparatus to encode substrates (e.g., paper, synthetics, etc.) with information. In one implementation a method is provided including: receiving data that corresponds to a two-dimensional signal that encodes plural bits of data; receiving data that corresponds to a frequency-domain signal, the data corresponding to a representation in a spatial domain through inverse transforming the frequency-domain signal; and defining characteristics for an element of a substrate-making process, the characteristics including at least a pattern representing the spatial domain representation and the two-dimensional signal.

Abstract: A digital watermark detection method uses a matched filtering technique on a log polar re-mapping of a watermarked signal to detect peaks associated with a repetitive structure of a watermark.

Abstract: Reversible watermarking methods enable auxiliary data to be embedded in data sets, such as images, audio, video and software. The reversible nature of the method enables the original data set to be perfectly restored. Control systems with feedback loops are used to optimize embedding based on distortion or auxiliary data capacity constraints. The watermarking may be applied recursively to embed several layers, where subsequent layers are embedded into a previously watermarked data set. To recover the original data, each layer is extracted and the data restored in reverse order of the embedding. Sets of elements that are expanded to carry auxiliary data in each layer overlap or are interleaved to maximize embedding capacity or quality of the host data.

Abstract: This disclosure describes several video watermarking and fingerprinting enhancements. These enhancements include synchronizing watermark detectors with one-dimensional calibration signals, layering digital watermarks, watermarks for version control, compressed domain watermarking, watermarking of video object layers, key channel watermark embedding for video, robust fingerprinting of video and watermarking of scalable video.

Abstract: The present invention provides methods and systems that are helpful authentication of physical and electronic documents like financial documents and identification documents. Steganographic indicia plays a role in some of our implementations. In other implementations we bind design features to a user or to a document. In still other implementations we provide authentication methods to evaluate security documents.

Abstract: The present invention relates generally to digital watermarking. In one implementation, we provide a hierarchical digital watermark detector method. The method includes: i) in a first layer of a hierarchical search, performing watermark detection on blocks of at least a portion of an incoming suspect signal; ii) identifying a first block in the portion that is likely to include a decodable digital watermark; and iii) in a second layer of the hierarchical search, performing additional watermark detection on overlapping blocks in a neighborhood around the first block. Another implementation provides a hierarchical watermark detector including a buffer and a detector. The buffer stores portions of an incoming signal. The detector evaluates watermark detection criteria for blocks stored in the buffer, and hierarchically zooms into a neighborhood of blocks around a block associated with watermark detection criteria that satisfies detection criteria.

Abstract: Digital watermark methods for encoding auxiliary data into a host signal are used to authenticate physical and electronic objects. One such method computes a content specific message dependent on the host signal, encodes the content specific message into a watermark signal, and embeds the watermark in the host signal such that the watermark signal is substantially imperceptible in the host signal. One specific implementation embeds data representing salient features of the host signal into the watermark. For example, for photo IDs, the method embeds the spatial location of salient features of the photo into the watermark. Another implementation computes a semi-sensitive hash of the host signal, such as a low pass filtering of the signal, and embeds the hash into the watermark. The watermark signal may be content dependent by making the watermark key dependent on some attribute of the signal in which the watermark is embedded.

Abstract: A text watermarking method embeds an auxiliary message in an original electronic text document to form a watermarked text document. The method applies a spreading function to message symbols to spread the symbols over a carrier, which forms a modulated carrier. It maps elements of the modulated carrier to corresponding inter-word spaces in the electronic text document, and applies an embedding function to modify the corresponding inter-word spaces according to elements of the modulated carrier signal such that the modified inter-word spaces hide the modulated carrier signal in the watermarked text document. The message symbols are automatically decodable from the watermarked document without the original electronic text document. A compatible decoder extracts the auxiliary message from a printed or electronic watermarked text document. The decoder automatically measures inter-word spaces in the watermarked text document.

Abstract: Digital watermark methods for encoding auxiliary data into a host signal are used to authenticate physical and electronic objects. One such method computes a content specific message dependent on the host signal, encodes the content specific message into a watermark signal, and embeds the watermark in the host signal such that the watermark signal is substantially imperceptible in the host signal. One specific implementation embeds data representing salient features of the host signal into the watermark. For example, for photo IDs, the method embeds the spatial location of salient features of the photo into the watermark. Another implementation computes a semi-sensitive hash of the host signal, such as a low pass filtering of the signal, and embeds the hash into the watermark. The watermark signal may be content dependent by making the watermark key dependent on some attribute of the signal in which the watermark is embedded.

Abstract: At least one region of each video frame is designated for intra encoding. One or more regions of each video frame are designated for inter encoding. One or more motion vectors are selected for each region designated for inter encoding, wherein at least one motion vector is a non-zero motion vector. The plurality of video frames are encoded in accordance with the designation of regions for intra encoding, the designation of regions for inter encoding, and the selection of motion vectors, wherein the designation of regions for intra encoding and the selection of motion vectors are adapted to ensure error recovery during decoding of the encoded video frames.

Abstract: A reference characterization characterizes the relationship between frames encoded using a first encoding process and frames encoded using a second encoding process for a variety of frames. A previous frame is encoded using the first encoding process and the encoded previous frame is characterized. A current frame is encoded using the second encoding process, wherein the current frame is encoded in accordance with the reference characterization and the characterization of the encoded previous frame.

Abstract: A cell of an image is segmented into two or more subcells. According to one embodiment, the nullity of each of the subcells is classified and the cell is encoded in accordance with the nullity of the subcells. According to another embodiment, the quantization level of each of the subcells is classified and the cell is encoded in accordance with the quantization levels of the subcells.

Abstract: A region of an image having a plurality of corresponding image values is encoded to generate a temporary encoded region. The temporary encoded region is then decoded to generate a decoded region. An error measure is generated as a function of the decoded pixels of the decoded region and the previous pixels of a previous region. If the error measure is less than a specified threshold, then the region is encoded as a skipped region, otherwise the region is encoded as the temporary encoded region.

Abstract: A similarity measure is generated as a function of a plurality of values corresponding to a region of an image. An encoding mode is then selected in accordance with the similarity measure and the region is encoded in accordance with the selected encoding mode.