Cisco Technology, Inc.

Arraycomm, Inc.

Barco Graphics, Nv

Dov Rosenfeld

Wen-hsiung Chen

John Albert Toebes

Fang Wu

Gregory Pelton

Mitchell D Trott

Paul Petrus

Michael Youssefmir

David M Parish

Alain M Chiodini

Ronny A De Loor

Gregory D Pelton

Disclosed are apparatuses, computer readable storage media with instructions that carry out methods, and methods of (a) coding quantized transform coefficients as occur in image compression to form codewords, and (b) decoding a bitstream comprising the codewords. The coding combines a position identifying method to identify the relative position of clusters of consecutive non-zero-valued quantized transform coefficients, an amplitude event identifying method to identify amplitude events in the clusters of non-zero-valued quantized transform coefficients, and a coding method to code the position events, amplitude events, and signs of the amplitudes in the clusters. The coding method is particularly applicable to an ordered series of quantized transform coefficients where clusters are likely-to-occur.

Variable length coding for clustered transform coefficients in video compression

Coding quantized transform coefficients as occur in image compression combines a position identifying method to identify the relative position of clusters of consecutive non-zero-valued coefficients, an amplitude event identifying method to identify amplitude events in the clusters of non-zero-valued coefficients, and a coding method to code the position events, amplitude events, and signs of the amplitudes in the clusters. The method is particularly applicable to a series of quantized transform coefficients where clusters are likely-to-occur.

Coding quantized transform coefficients as occur in image compression combines a position identifying method to identify the relative position of clusters of consecutive non-zero-valued coefficients, an amplitude event identifying method to identify amplitude events in the clusters of non-zero-valued coefficients, and a coding method to code the position events, amplitude events, and signs of the amplitudes in the clusters. The method is particularly applicable to a series of quantized transform coefficients where clusters are likely to occur.

For data compressed using the first compression method that includes codewords generated by variable length coding sets of quantized transform coefficients using a first variable length coding method, decoding the codewords to create ordered sets of quantized transform coefficients, each created set forming an ordered series of quantized transform coefficients, and re-encoding the created ordered sets of quantized transform coefficients using a second variable length coding method to produce a re-coded set of codewords. The second variable length coding method produces shorter codewords, on average, than the first variable length coding method. The decoding and re-encoding is a lossless process such that no additional quantization or other errors are introduced to the received data by the method.

Losslessly improving compression of compressed image data

A method, apparatus, and carrier medium to encode a series of quantized transform coefficients. The method includes identifying events that each includes a run of zero-valued coefficients preceding a run of one or more non-zero-valued coefficients, and for each such event, jointly encoding the run lengths of the preceding run of zero-valued coefficients and the following run of non-zero-valued coefficients with a codeword, such that for at least some events, relatively more likely-to-occur pairs of runlengths are encoded by a shorter codeword than relatively less likely-to-occur runlengths. The method further includes encoding each amplitude in the run of consecutive non-zero-valued coefficients, and encoding the signs of such coefficients. The method is applicable to encoding a region in the series where there is likely to be a cluster of non-zero-valued coefficients.

Two-dimensional variable length coding of runs of zero and non-zero transform coefficients for image compression

A method for generating a reference signal from a modulated signal transmitted to a communications station that includes an array of antenna elements and spatial processing means including: separating from the signals received at the antenna elements a copy signal corresponding to the signal transmitted by a particular remote station using an initial spatial weight vector corresponding to the particular remote station; determining from the terminal copy signal a reference signal having substantially the same frequency offset and time alignment as the received antenna signals; and computing a new spatial weight vector by optimizing a cost function, the cost function using the received antenna signals and the reference signal. For demodulation, the method further includes extracting the symbols of the modulated signal.

Method for reference signal generation in the presence of frequency offsets in a communications station with spatial processing

A method and system for exposing a light sensitive material using device for forming a row of spots of light onto the light sensitive material located on a focal plane, device for modulating each of the spots according to imaging data so that at any point of time, the row of spots forms a data pattern according to the imaging data, device for generating relative motion between the imaging mechanism and the light sensitive material on the focal plane, the direction of motion substantially parallel to the direction of the row of spots on the light sensitive material; and data synchronizing device for shifting the imaging data into the modulating device at a rate determined by the speed of relative motion to maintain the image of any data pattern substantially stationary on the light sensitive material.

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Oakland, CA, United States of America

Dov Rosenfeld