Albert E Rackett

6567469, May 20, 2003

Mar 23, 2000

09/533487

Albert E. Rackett - Milpitas CA

Koninklijke Philips Electronics N.V. - Eindhoven

H04N 712

37524016, 348699

A method for identifying an optimum motion vector for a current block of pixels in a current picture in a process for performing motion estimation. The method is implemented by evaluating a plurality of motion vector candidates for the current block of pixels by, for each motion vector candidate, and calculating an error value that is representative of the differences between the values of the pixels of the current block of pixels and the values of a corresponding number of pixels in a reference block of pixels. While evaluating each motion vector candidate, the error value is checked, preferably at several points, while calculating the error value, and the evaluation is aborted for that motion vector candidate upon determining that the error value for that motion vector candidate exceeds a prescribed threshold value. The motion vector candidate that has the lowest calculated error value is selected as the optimum motion vector for the current block of pixels. The motion vector candidates are preferably evaluated in two distinct phases, including a first phase that includes evaluating a subset of the motion vector candidates that have an intrinsically high probability of being the optimum motion vector candidate, and a second phase that includes performing a spatial search within a prescribed search region of a reference picture in order to identify a different reference block of pixels within the prescribed search region for each respective motion vector candidate evaluation.

6668095, Dec 23, 2003

Apr 17, 2001

09/836084

Albert E. Rackett - Milpitas CA

Koninklijke Philips Electronics N.V. - Eindhoven

G06K 936

382250, 382233, 3752402

This invention relates to systems and methods for increasing image compression. The systems and methods are improvements applicable to encoder/decoders which compress images by, inter alia, transforming non-overlapping independent blocks of pixels into a frequency domain and then quantizing the resulting frequency domain coefficients. The invention achieves increased compression by predicting low frequency coefficients of a block from, preferably, the average intensities, or zero frequency coefficients, of the block and its adjacent blocks. In an encoder, the low frequency coefficients are predicted, are then subtracted from the actual transform coefficients, and the difference coefficients are transmitted to a decoder. In the decoder, the low frequency coefficients are again predicted, are added to the received difference coefficients, and the resulting actual transform coefficients are used to reconstruct an image.

6873654, Mar 29, 2005

May 15, 2001

09/858340

Albert E. Rackett - Milpitas CA, US

Redrock Semiconductor, Inc - Sunnyvale CA

H04N007/12

37524003

A technique for digital video processing in a predictive manner is provided. In one embodiment, a method for processing digital video signals for live video applications comprises providing video data that comprise a plurality of frames, identifying a first frame and a second frame in the frame sequences, and processing the information of the first frame and the information of the second frame to determine a quantization step for the second frame. The step of processing the information of the first frame and the information of the second frame further comprises calculating a sigmaSAD value for the second frame, calculating a divisor value for the second frame, and calculating the quantization step for the second frame. In another embodiment, a system for processing digital video signals for live video applications comprises a memory unit within which a computer program is stored. The computer program instructs the system to process digital video in a predicative manner.

62823221, Aug 28, 2001

Dec 3, 1998

9/207835

Albert E. Rackett - Milpitas CA

Philips Electronics North America Corp. - New York NY

G06K 936

382248

This invention relates to systems and methods for increasing image compression. The systems and methods are improvements applicable to encoder/decoders which compress images by, inter alia, transforming non-overlapping independent blocks of pixels into a frequency domain and then quantizing the resulting frequency domain coefficients. The invention achieves increased compression by predicting low frequency coefficients of a block from, preferably, the average intensities, or zero frequency coefficients, of the block and its adjacent blocks. In an encoder, the low frequency coefficients are predicted, are then subtracted from the actual transform coefficients, and the difference coefficients are transmitted to a decoder. In the decoder, the low frequency coefficients are again predicted, are added to the received difference coefficients, and the resulting actual transform coefficients are used to reconstruct an image.

63175223, Nov 13, 2001

Dec 3, 1998

9/204178

Albert E. Rackett - Milpitas CA

Philips Electronics North America Corp. - New York NY

G06T 900

382268

This invention relates to a system and method for reducing blocking artifacts introduced by current compression algorithms that compress images as independent blocks of pixels. Preferably, the methods of the invention include determining block-to-block differences in edge pixels or in overall intensities between adjacent pixel blocks, selecting pixel blocks for post-processing that appear to be in relatively featureless regions of the image, interpolating the block-to-block edge differences into a error correction matrix, and then subtracting the error correction matrix from the original pixel block. These methods are preferably implemented in special software routines that execute on micro-processor based systems or on digital signal processor based systems optimized for image decoding.

47046287, Nov 3, 1987

Jul 16, 1986

6/886634

Wen-hsiung Chen - Sunnyvale CA
James P. Elliott - Cupertino CA
Robert E. G. Newell - San Jose CA
Ralph E. Nichols - Los Gatos CA
Albert E. Rackett - Sunnyvale CA

Compression Labs, Inc. - San Jose CA

H04N 712
H04N 7133
H04N 7137

358136

An apparatus and method for signal processing employing intraframe and interframe variable prediction transform coding. Images are represented by sequential frames of two-dimensional arrays of digital signals. The digital signals are transformed to form transform coefficients for each frame. Predicted transform coefficients are formed using sets of variable prediction factors. The predicted transform coefficients for each frame are compared with corresponding actual transform coefficients for the frame to form transform coefficient difference signals. The difference signals are processed to control their range of values. The processed difference signals are statistically coded such that the more frequently occurring values are represented by shorter code lengths and the less frequently occurring values are represented by longer code lengths. The coded signals are stored in a buffer memory for transmission.