Abstract: A system and method for adaptive estimation and compensation of clock drift in echo cancellers is provided. The invention includes an acoustic echo cancellation system with a built in adaptive clock drift compensation system. The acoustic echo cancellation system has an AEC component that performs acoustic echo cancellation on data from a capture buffer, by also using information derived from a render buffer. The clock drift compensation system has access to this capture buffer and render buffer. The clock drift compensation system includes a clock drift compensator that calculates, based on the current location of the capture data being processed by the AEC component as well as additional information, the ideal location in the render buffer from which the AEC component should process data. The clock drift compensator further adjusts the current location in the render buffer from which the AEC component processes data based, at least in part, upon this ideal location.

Abstract: An implementation of a technology is described herein that facilitates rights enforcement of digital goods using watermarks. More particularly, it is a fingerprinting technology for protecting digital goods by detecting collusion as a malicious attack and identifying the participating colluders. If a digital pirate breaks one client and enables this client to avoid watermark detection, all content (both marked/protected an unmarked/free) can be played as unmarked only on that particular client. However, to enable other clients to play content as unmarked, the digital pirate needs to collude the extracted detection keys from many clients in order to create content that can evade watermark detection on all clients. The described implementation significantly improves collusion resistance through a fingerprinting mechanism that can identify the members of a malicious coalition even when their numbers are several orders of magnitude greater than what conventional collusion-protection schemes can accomplish.

Abstract: A adaptive filter interpolation method and system for the demosaicing of color images. In general, input pixels are input in a Bayer-mosaiced pattern (only one color per pixel), and output pixels are in full RGB mode (three color values per pixel). For each pixel location, in raster scan order, the processing steps can be summarized as follows. Following a regular raster scanning order (from left to right and top to bottom), for each pixel location horizontal and vertical gradients are first computed (whose computation depends on the available color for that pixel), and from those the appropriate interpolation filters are chosen from a small set of predetermined filters. Then, the chosen filters are applied to interpolate the missing data.

Abstract: An implementation of a technology is described herein that facilitates rights enforcement of digital goods using watermarks. More particularly, it is a fingerprinting technology for protecting digital goods by detecting collusion as a malicious attack and identifying the participating colluders. If a digital pirate breaks one client and enables this client to avoid watermark detection, all content (both marked/protected an unmarked/free) can be played as unmarked only on that particular client. However, to enable other clients to play content as unmarked, the digital pirate needs to collude the extracted detection keys from many clients in order to create content that can evade watermark detection on all clients. The described implementation significantly improves collusion resistance through a fingerprinting mechanism that can identify the members of a malicious coalition even when their numbers are several orders of magnitude greater than what conventional collusion-protection schemes can accomplish.

Abstract: Described herein is a watermarking technology for protecting digital signals, such as a music clip. In another described implementation, a watermarking system employs a permutation technique to hide a watermark. The order in which data is imposed or encoded is rearranged may be based upon a permutation table. The same table may be used to reverse permute the data at the detector.

Abstract: Audio signals, such as a music clip, are inserted with detectable watermarks. The inserted watermark can identify the content producer and provide a signature embedded in the audio signal and cannot be removed. The watermark can survive all typical kinds of processing and malicious attacks. The watermark can be implemented in a watermarking system that employs a covert channel encoder to layer an additional information data message or covert message on top of the watermark. The watermarking system can also include a permutation technique to further hide the watermark and hide the covert message within the watermark.

Abstract: A scrambling architecture protects data streams in the operating system and hardware components of a computer by scrambling the otherwise raw data prior to the data being handled by the operating system. Scrambled content is passed to a filter graph (or other processing system) where the content is processed while scrambled. A scrambler also generates a random signal based on a first key and a second key. After processing, the scrambled data is passed to a driver for output. A driver may implement a descrambler to detect tone patterns in the content and recovers the first key from varying amplitudes of the tone patterns. The descrambler may also receive the second key via a separate channel and generates the same random signal using the recovered first key and the second key. The descrambler subtracts the tone patterns and the random signal from the scrambled content to restore the content.

Abstract: A new color space that maps image pixel values in a mosaiced sampling pattern (such as that generated by a Bayer color filter array) into four color channels that correspond to rectangular sampling patterns. Because these new channels correspond to a rectangular sampling grid, they are much more amenable to processing steps such as compression. In one embodiment, the transformation from the original mosaic-patterned pixels into the new four-channel color space can be made reversible in integer arithmetic. That allows for the implementation of efficient lossless image compression systems for mosaiced (e.g., raw, or raw Charged Couple Device (CCD)) images.

Abstract: An analog preamplifier measurement system for a microphone array builds on conventional microphone arrays by providing an integral “self-calibration system.” This self-calibration system automatically injects an excitation pulse of a known magnitude and phase to all preamplifier inputs within the microphone array. The resulting analog waveform from each preamplifier output is then measured. A frequency analysis, such as, for example, a Fourier or Fast Fourier Transform (FFT), or other conventional frequency analysis, of each of the resulting waveforms is then performed. The results of this frequency analysis are then used to automatically compute frequency-domain compensation gains (e.g., magnitude and phase gains) for each preamplifier for matching or balancing the responses of all of the preamplifiers with each other.

Abstract: The ability to combine multiple audio signals captured from the microphones in a microphone array is frequently used in beamforming systems. Typically, beamforming involves processing the output audio signals of the microphone array in such a way as to make the microphone array act as a highly directional microphone. In other words, beamforming provides a “listening beam” which points to a particular sound source while often filtering out other sounds. A “generic beamformer,” as described herein automatically designs a set of beams (i.e., beamforming) that cover a desired angular space range within a prescribed search area. Beam design is a function of microphone geometry and operational characteristics, and also of noise models of the environment around the microphone array. One advantage of the generic beamformer is that it is applicable to any microphone array geometry and microphone type.

Abstract: Described herein is a technology for facilitating watermark detection. Spread-spectrum watermarking is a commonly employed technique for hiding data in digital goods (e.g., multimedia signals). Such watermarks may be potentially vulnerable to so-called “watermark estimation-based attacks.” At least one implementation, described herein, is an advancement over the traditional spread-spectrum watermark detector. At least one implementation, described herein, greatly discourages an estimation-based attack by an adversary. At least one implementation, described herein, determines whether a digital good has likely been subjected to an estimation-based attack and, at least, approximately reverses such attack. The scope of the present invention is pointed out in the appending claims.

Abstract: A system and method for embedding information into digital media and later detecting the embedded information using a unique spread spectrum modulation technique. In general, the present invention removes interference caused by an original signal from the detection process thereby eliminating a major source of detection error. The interference caused by the original signal is removed by using the encoder knowledge about the original signal and modulating the energy of the embedded mark to compensate for the original signal interference. The present invention also includes a novel redundant bit representation technique causes a resulting average over a large sample to tend to zero, thereby reducing the vulnerability of the present invention to malicious collusion attacks.

Abstract: Systems and methods for encoding and decoding document images are disclosed. Document images are segmented into multiple layers according to a mask. The multiple layers are non-binary. The respective layers can then be processed and compressed separately in order to achieve better compression of the document image overall. A mask is generated from a document image. The mask is generated so as to reduce an estimate of compression for the combined size of the mask and multiple layers of the document image. The mask is then employed to segment the document image into the multiple layers. The mask determines or allocates pixels of the document image into respective layers. The mask and the multiple layers are processed and encoded separately so as to improve compression of the document image overall and to improve the speed of so doing. The multiple layers are non-binary images and can, for example, comprise a foreground image and a background image.

Abstract: A system and method facilitating compression of bi-level images with explicit representation of ink clusters is provided. The present invention includes a cluster shape estimator that analyzes connected component information, extracts clusters and stores the cluster in a global dictionary, a page dictionary or a store of unclustered shapes. A bitmap estimation from clusters component determines dictionary positions for clusters stored in the global dictionary which are then encoded. A cluster position estimator determines page positions of clusters of the global dictionary and/or the page dictionary that are then encoded. Further, the global dictionary, the page dictionary and the store of unclustered shapes are also encoded.

Abstract: Described herein is audio watermarking technology for inserting and detecting watermarks in audio signals, such as a music clip. The watermark identifies the content producer, providing a signature that is embedded in the audio signal and cannot be removed. The watermark is designed to survive all typical kinds of processing and malicious attacks. In one described implementation, a watermarking system employs chess spread-spectrum sequences (i.e., “chess watermarks”) to improve the balance of positive and negative chips in the watermarking sequences. The balance is not imposed in an orderly fashion, which might make the watermark sequence more easily detectable to an attacker, but in a pseudo-random fashion. In that way, better sequence balance is achieved while preserving its randomness for an attacker without knowledge of the keys.

Abstract: A watermark encoding system encodes an audio signal with both a strong and a weak watermark. The strong watermark identifies the content producer and is designed to survive all typical kinds of processing and malicious attacks. The weak watermark identifies the content as an original and is designed to be significantly removed as a result of most normal signal processing (other than A/D and D/A). The watermark encoding system has a converter to convert an audio signal into frequency and phase components and a mask processor to determine a hearing threshold for corresponding frequency components. The watermark encoding system also has a pattern generator to generate both the strong and weak watermarks and a watermark insertion unit to selectively insert either the strong or weak watermark into the audio signal. The watermark insertion unit adds the strong watermark to the audio signal when the signal exceeds the hearing threshold by a buffer value (e.g.

Abstract: A watermark encoding system encodes an audio signal with both a strong and a weak watermark. The strong watermark identifies the content producer and is designed to survive all typical kinds of processing and malicious attacks. The weak watermark identifies the content as an original and is designed to be significantly removed as a result of most normal signal processing (other than A/D and D/A). The watermark encoding system has a converter to convert an audio signal into frequency and phase components and a mask processor to determine a hearing threshold for corresponding frequency components. The watermark encoding system also has a pattern generator to generate both the strong and weak watermarks and a watermark insertion unit to selectively insert either the strong or weak watermark into the audio signal. The watermark insertion unit adds the strong watermark to the audio signal when the signal exceeds the hearing threshold by a buffer value (e.g.

Abstract: A system and method for adaptive estimation and compensation of clock drift in echo cancellers is provided. The invention includes an acoustic echo cancellation system with a built in adaptive clock drift compensation system. The acoustic echo cancellation system has an AEC component that performs acoustic echo cancellation on data from a capture buffer, by also using information derived from a render buffer. The clock drift compensation system has access to this capture buffer and render buffer. The clock drift compensation system includes a clock drift compensator that calculates, based on the current location of the capture data being processed by the AEC component as well as additional information, the ideal location in the render buffer from which the AEC component should process data. The clock drift compensator further adjusts the current location in the render buffer from which the AEC component processes data based, at least in part, upon this ideal location.

Abstract: Systems and methods for encoding and decoding document images are disclosed. Document images are segmented into multiple layers according to a mask. The multiple layers are non-binary. The respective layers can then be processed and compressed separately in order to achieve better compression of the document image overall. A mask is generated from a document image. The mask is generated so as to reduce an estimate of compression for the combined size of the mask and multiple layers of the document image. The mask is then employed to segment the document image into the multiple layers. The mask determines or allocates pixels of the document image into respective layers. The mask and the multiple layers are processed and encoded separately so as to improve compression of the document image overall and to improve the speed of so doing. The multiple layers are non-binary images and can, for example, comprise a foreground image and a background image.

Abstract: A transform coder is described that performs a time-split transform in addition to a discrete cosine type transform. A time-split transform is selectively performed based on characteristics of media data. Transient detection identifies a changing signal characteristic, such as a transient in media data. After encoding an input signal from a time domain to a transform domain, a time-splitting transformer selectively perform an orthogonal sum-difference transform on adjacent coefficients indicated by a changing signal characteristic location. The orthogonal sum-difference transform on adjacent coefficients results in transforming a vector of coefficients in the transform domain as if they were multiplied by an identity matrix including at least one 2×2 time-split block along a diagonal of the matrix. A decoder performs an inverse of the described transforms.