Koninklijke Philips Corporation N.V.

Philips Electronics North America Corporation

Redrock Semiconductor, Inc.

Albert E Rackett

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. In yet another embodiment, a system for processing digital video signals for live video applications comprises various subsystems that together process digital video in a predictive manner.

Method and system for predictive control for live streaming video/audio media

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.

Systems and methods for compressing and decompressing images

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. The subset of motion vector candidates preferably includes a first motion vector candidate that corresponds to a location of the reference block of pixels in a reference picture that is the same as the location of the current block of pixels in the current picture, a second motion vector candidate that corresponds to a location of the reference block of pixels in a previous picture that is the same as the location of the current block of pixels in the current picture, and a third motion vector candidate that constitutes an optimum motion vector previously determined for a preceding block of pixels in the current picture. Preferably, no further evaluations are performed if it is determined that the error value for the first motion vector candidate is below a prescribed motion estimation termination threshold value. The method is executed by software that operates a software-implemented state machine. The software preferably includes source code that defines a search sequence, and a function that builds the state machine in a prescribed memory space.

Motion estimation algorithm suitable for H.261 videoconferencing applications

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.

Growing community of inventors

Milpitas, CA, United States of America

Albert E Rackett