Mesh node motion coding to enable object based functionalities within a motion compensated transform video coder

• US 6,339,618 B1
• Filed: 05/31/2000
• Issued: 01/15/2002
• Est. Priority Date: 01/08/1997
• Status: Expired due to Term

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: van Beck, Petrus J. L., Puri, Atul, Tekalp, A. Murat
• Primary Examiner(s): BRITTON, HOWARD W
• Application Number:
  US09/584,176
• Time in Patent Office: 594 Days
• Field of Search: 375/240.16, 375/240, 382/243, 382/232, 382/233, 382/236, 382/238, 382/241, 348/384.1, 348/390.1, 348/397.1, 348/402.1, 348/409.1, 348/415.1, 348/416.1, 348/420.1, 348/699
• US Class Current: 375/240.16
• CPC Class Codes: H04N 19/29 involving scalability at the object level, e.g. video object layer [VOL]
• CPC Class Codes: H04N 19/537 Motion estimation other than block-based
• CPC Class Codes: H04N 19/54 using feature points or meshes

Abstract

A method and apparatus for coding video data permits coding of video information with optional, enhanced functionalities. Video data is coded as base layer data and enhancement layer data. The base layer data includes convention motion compensated transform encoded texture and motion vector data. Optional enhancement layer data contains mesh node vector data. Mesh node vector data of the enhancement layer may be predicted based on motion vectors of the base layer. Thus, simple decoders may decode the base layer data and obtain a basic representation of the coded video data. However, more powerful decoders may decode both the base layer and enhanced layer to obtain decoded video permitting functionalities. An embodiment of the present invention provides a back channel that permits a decoder to affect how mesh node coding is performed in the encoder. The decoder may command the encoder to reduce or eliminate encoding of mesh node motion vectors. The back channel finds application in single layer systems and two layer systems.

Claims

1. A channel carrying thereon coded video data including, in a first layer, block-based texture data and block-based motion data and, in a second layer, mesh node-based motion data, wherein decodable video data may be obtained solely from texture data and motion data of the first layer.

2. The channel of claim 1, wherein the mesh node based motion data is residual data to supplement a prediction based on the block-based motion data.

3. The channel of claim 1, wherein the channel is a memory.

4. The channel of claim 1, wherein the channel is a communication channel.

5. A video data signal generated according to the process of:

generating decoded video data based upon coded block-based texture data and coded block-based motion data,

generating synthetic data based upon coded mesh-node-based motion data representative of the decoded video data and overlay image data, and

outputting a composite video data signal based upon the decoded video data and the synthetic data signal.

6. The video data signal of claim 5, wherein the mesh-node based motion data is residual data reflecting a mesh-node motion prediction made with reference to the co-located block-based motion data.

8. The video decoder of claim 5, wherein the compositor predicts motion data based upon the block-based motion data and the mesh-node motion data.

7. A video decoder, comprising

a base layer decoder that generates decoded video data from coded block-based texture data and coded block-based motion data received from a channel, and

a compositor that generates synthetic video data based upon mesh node motion data received from the channel and externally supplied image data, the compositor superimposing the synthetic video data over co-located decoded video data.