Massachusetts Institute of Technology

Andrew Benjamin Lippman

Edward H Adelson

Joseph A Paradiso

Hongshen Ma

William J Butera

Ernesto E Blanco

David P Reed

William F Schreiber

Walter R Bender

Victor Michael Bove, Jr

Grace Rusi Woo

Aggelos Bletsas

Jerome B Wiesner

Travis Rich

Aran N Netravali

Phyllis K Kristal

Pascal R Chesnais

Patrick G McLean

System for conveying a stream of information. The system includes an encoding device employing a spatio-temporal coding scheme that omits light, including codes embedded therein that are invisible to a user. A receiver that might be a cell phone camera receives light from the encoding device and computer apparatus is programmed with software to decode the received light to generate the stream of information. The encoding device is preferably a video display.

Video codes for encoding/decoding streaming data

In exemplary implementations of this invention, a manufactured physical object includes surface features that encode information according to a code. Each respective surface feature consists of a bump on, or recess in, a surface of the object. Each respective surface feature by itself, regardless of any state of any other surface feature, encodes a sequence of multiple bits. The sequence is determined, at least in part, by a discrete elevation of the respective surface feature. At least three different discrete elevations of surface features are significant in the code. Also, one or more other parameters of the surface features may be significant in the code, such as discrete rotational orientation, discrete overall shape, discrete color, or presence or absence of the feature.

Methods and apparatus for encoded textures

A method and system provide routing of signals through a communications network. A transmitted signal is received. The signal has an associated parameter that is monitored as the signal is received. The parameter indicates the extent to which prior retransmission of the signal has occurred. The signal is retransmitted only if its parameter satisfies at least one predetermined criterion.

Method for automatic signal routing in ad hoc networks

A quasi-passive wake-up function for an electronic device that employs a continuous low power standby mode compares a received signal to a predetermined signal and wakes up the device when the received signal is the same as the predetermined signal. An electronic device having a quasi-passive wakeup function includes a receiver for receiving at least one stimulus signal, a comparator for comparing the received signal to a predetermined signal, and at least one logic gate for waking up the electronic device when the received stimulus signal is the predetermined signal. In one application, identification tags are used to distinguish a unique tagged item from among a plurality of items with a similar appearance. When an interrogation signal is not present, the tags sleep at a very low power level.

Quasi-passive wakeup function to reduce power consumption of electronic devices

An identification tag identifies a unique item from among a plurality of items with a similar appearance. Tagged items are searched by scanning the items with an interrogation signal. The tag emits an observable signal to indicate when it receives an identification that matches the identification contained in the tag. When the reader's interrogation is not present, the tag either sleeps at a very low power level or is passively unpowered.

Tag interrogation with observable response signal

A method of processing video data created for display in one aspect ratio in a plurality of different sequences of frames thereof, each frame in a sequence containing background data which represents at least a part of the same relatively stationary background data in the sequence. The background data in each frame of a sequence is stored and processed so as to produce combined background data representing the background image in the sequence in a different aspect ratio, without the presence of moving objects therein. Data representing moving objects in each frame of a sequence are stored together with selected portions of the background data which surround the moving objects in each frame. The data representing moving objects in each frame are correctly positioned in the combined background data, which is used for each frame of the sequence, by matching the selected portion of the background data surrounding the moving objects with corresponding portions of the combined background data to determine the correct positions of the moving objects in the background image. The background data and the matching portions of the moving objects are composited in accordance with such correct position determination to form a composite image for each frame in which the moving objects are correctly positioned in the combined background image.

Video image compositing techniques

A television encoder for generating a receiver-compatible signal from a production video signal containing enhancement information which cannot be displayed on a standard receiver, the receiver-compatible signal being compatible with the standard receiver, the encoder including a filter bank for dividing the video signal into at least two groups of spatial frequency components including a first group and a second group, the first group containing members which when combined together form a standard video signal which is displayed by the standard receiver and the second group containing the enhancement information; a quantizer for quantizing at least one member of the first group; a combiner for adding at least one member of the second group to a quantized member of the first group to produce a modified first group; and a synthesizer for combining the members of the modified first group to generate the receiver-compatible signal.

Receiver-compatible enhanced definition television system

A position sensing system which allows the arthroscopist to readily determine the location of an arthroscope's tip in relation to the point of entry has been developed. The position sensing apparatus can be employed in conjunction with a graphics module to display the location of the arthroscope in real time and provide perspective views of the instrument's location.

Video-graphic arthroscopy system

Methods and systems for adding additional information to broadcast motion picture signals so that an advanced receiver can decode that information to provide improved picture quality, while a standard receiver will display an image with minimally visible impairments. In particular, chrominance information can be generated at a fraction of the frame rate and the alternate frames then used to encode additional data, such as high definition luminance information in the chrominance signal.

Extended definition television systems

Image encoding apparatus and methods include recursively decomposing the luminance values of sequential frames into spatio-temporal spectral components, by quadrature mirror filter (QMF) processing of the luminance values. The filtered signals are subsampled, and each decomposed level of the spectral components is coded by vector quantization.

Multiscale coding of images

A technique for handling video signals so as to permit such signals to be satisfactorily displayed on video display devices, such as TV receivers or monitors, but to prevent such signals from being satisfactorily recorded by video recording devices. In a particular embodiment thereof the video frame time base is altered in a selected manner, as by lengthening or shortening the time bases of successive video frames, or successive groups of video frames. The alterations thereof can be in discrete steps and be performed cyclically so that during each overall cyclical time period the cumulative error is zero.

Growing community of inventors

Salem, MA, United States of America

Andrew Benjamin Lippman