Apple Inc.

Alexei V Ouzilevski

Brett C Bilbrey

Jay Zipnick

Fernando A Urbina

Sushma Shrikant Trivedi

Steven Todd Weybrew

Harry Guo

Joseph P Bratt

Mushtaq A Sarwar

Ronald Gerard Langhi

Yutaka Takahashi

Systems and techniques for processing sequences of video images involve receiving, on a computer, data corresponding to a sequence of video images detected by an image sensor. The received data is processed using a graphics processor to adjust one or more visual characteristics of the video images corresponding to the received data. The received data can include video data defining pixel values and ancillary data relating to settings on the image sensor. The video data can be processed in accordance with ancillary data to adjust the visual characteristics, which can include filtering the images, blending images, and/or other processing operations.

Video acquisition with processing based on ancillary data

Video acquisition with integrated GPU processing

A post-processing manager provides reconstructed block based picture post-processing that is uncoupled from picture decoding by dividing a reconstructed image that was encoded using block based processing into non-overlapping blocks, creating a DC image by computing the DC value of each block, creating a zero mean image by subtracting the DC value of each block from the corresponding pixels of that block, filtering the DC image and adding the filtered DC image to the zero mean image. A weak filtering operation can be applied to reduce blocking artifacts, and a strong filtering operation can be applied to smooth luminance transitions.

Reducing undesirable block based image processing artifacts by DC image filtering

A temporal dithering manager uses temporal dithering to reduce contouring artifacts due to bit limiting. The temporal dithering manager truncates low order bits of an input signal, creates a temporal dither signal based on the truncated low order bits and applies the temporally created dither signal to the truncated signal. A temporal filtering manager applies a temporal filter to the truncated signal, thereby improving the quality of the truncated signal. The temporal dithering can be applied at a preprocessing stage, and the temporal filtering at a post-processing stage.

Robust temporal dithering and filtering

Methods and apparatuses for transposing a matrix using a vector look up unit. In one aspect of the invention, a method for matrix transposition includes: rotating in a vector register a first row of a matrix to generate a first row, of elements; writing simultaneously into a plurality of look up units the first row of elements indexed by a first row of indices in a vector register; looking up simultaneously from the plurality of look up units a second row of elements indexed by a second row of indices in a vector register; and rotating in a vector register the second row of elements to generate a third row of elements.

Method and apparatus for matrix transposition

Methods and apparatuses for converting color components in one space to those in another space. In one aspect of the invention, a method for vector conversion including: loading a first vector of components into a vector register; generating a first vector of indices in a vector register, each index of the first vector of indices being one of the first vector of components, at least one component in the first vector of components being replicated as a plurality of duplicated indices in the first vector of indices; looking up simultaneously a first vector of data items from a plurality of look up tables using the first vector of indices; and summing up at least one subset of the first vector of data items into at least one component of a second vector of components.

Method and apparatus for color space conversion

Methods and apparatuses for decoding a compressed video stream. In one aspect of the invention, a method to decode a variable length encoded bit stream includes: concurrently processing first data obtained from variable length decoding a first code word in a register while variable length decoding a second code word in the register. In one example, processing the first data includes: looking up an inverse zigzag index; computing an Inverse Direct Cosine Transformation (IDCT) coefficient; storing the IDCT coefficient in a buffer in a transposed inverse zigzag order; and branching conditionally based on a condition encountered in variable length decoding the first code word.

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Cupertino, CA, United States of America

Alexei V Ouzilevski