US 8,027,385 B2 · Efficient video coding

Abstract

A method (1600) and apparatus (220) for encoding a sequence of images for transmission over a communication network is disclosed. Initially (1602) an object-based first image is rendered from a computer graphics application (240). The rendered first image is then (1604) encoded (226) according to a predetermined encoding scheme and transmitted (1606) for remote display (116). A test (1608) is then performed to determine if any more images are to be rendered. If so, the next (further) image is rendered (1612) from the computer graphics application (240). Changes between the first image and the further image are then determined (1614) from a change indicating output (244,246) of the computer graphics application (240). The identified changes are then used (1616) to determine a manner in which the further image is to be encoded according to the predetermined format. The further image is then encoded (1618) based upon the changes, and transmitted (1620) for remote display. Further images are rendered and encoded using changes from the preceding image.

Claims18

Dependent claims

A computer-implemented method of encoding a first image and a second image in a sequence of images of a video stream for transmission over a communication network, said computer running an object-based computer graphics application, the method comprising the steps of:

(i) rendering a first portion of the first image from a display list in the object-based computer graphics application;
(ii) encoding the first portion according to a predetermined encoding scheme;
(iii) rendering a second portion of the second image at a corresponding location of the first portion from the display list in the object-based computer graphics application;
(iv) interpreting the display list in the computer graphics application to identify changes between the first image and the second image and an attribute of an object at the location of the rendered portion;
and
(v) using the identified changes and the attribute of the object to determine an amount of quantization in which the second image is encoded according to the predetermined encoding scheme.

3 more elements

Apparatus for encoding a first image and a second image in a video stream for transmission over a communication network, said apparatus comprising:

a graphics processor, adapted to form display list representations of plural graphic object-based images including the first image and the second image by executing an object-based computer graphics application;
a renderer, adapted to render from the display list a first portion of the first image and a second portion of the second image at a corresponding location of the first image;
an interpreter configured to interpret the display list in the computer graphics application to identify changes between the first image and the second image and an attribute of an object at the location of the rendered portion;
and
an encoder, adapted to encode the first portion according to a predetermined encoding scheme and to use the identified change and the attribute of the object to determine an amount of quantization in which the second image is encoded according to the predetermined encoding scheme.

2 more elements

A computer readable storage medium having a program recorded thereon, the program being executable in a computer to encode a first image and a second image in a sequence of images of a video stream for transmission over a communication network, said computer running an object-based computer graphics application, the program comprising:

code for rendering a first portion of the first image from a display list in the object-based computer graphics application;
code for encoding the first portion according to a predetermined encoding scheme;
code for rendering a second portion of the second image at a corresponding location of the first portion from the display list in the object-based computer graphics application;
code for interpreting the display list in the computer graphics application to identify changes between the first image and the second image and an attribute of an object at the location of the rendered portion;
and
code for using the identified changes and the attribute of the object to determine an amount of quantization in which the second image is encoded according to the predetermined encoding scheme.

3 more elements

Dependencies are inferred from the claim text.

Efficient video coding

Life of this patent

Efficient video coding

Life of this patent

Abstract

Claims18