Optimization of intra block size in video coding based on minimal activity directions and strengths

• US 9,307,250 B2
• Filed: 01/14/2014
• Issued: 04/05/2016
• Est. Priority Date: 11/16/2011
• Status: Active Grant

• Current Assignee: Beamr Imaging Ltd.
• Original Assignee: Vanguard Video LLC (Beamr Ltd.)
• Inventors: Zheludkov, Alexander C., Martemyanov, Alexey, Terterov, Nikolay
• Primary Examiner(s): LEE, Y YOUNG
• Application Number:
  US14/154,684
• Publication Number:
  US 20140126634A1
• Time in Patent Office: 812 Days
• Field of Search: 375/240.01, 375/240.12, 375/240.24, 375/240.26
• US Class Current: 1/1
• CPC Class Codes: H04N 19/11 among a plurality of spatial predictive coding modes
• CPC Class Codes: H04N 19/119 Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/139 Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability
• CPC Class Codes: H04N 19/14 Coding unit complexity, e.g. amount of activity or edge presence estimation H04N19/146 takes precedence
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/19 using optimisation based on Lagrange multipliers
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/513 Processing of motion vectors
• CPC Class Codes: H04N 19/52 by predictive encoding
• CPC Class Codes: H04N 19/521 for estimating the reliability of the determined motion vectors or motion vector field, e.g. for smoothing the motion vector field or for correcting motion vectors
• CPC Class Codes: H04N 19/523 with sub-pixel accuracy
• CPC Class Codes: H04N 19/53 Multi-resolution motion estimation; Hierarchical motion estimation
• CPC Class Codes: H04N 19/533 Motion estimation using multistep search, e.g. 2D-log search or one-at-a-time search [OTS]
• CPC Class Codes: H04N 19/567 Motion estimation based on rate distortion criteria
• CPC Class Codes: H04N 19/593 involving spatial prediction techniques
• CPC Class Codes: H04N 19/65 using error resilience

Abstract

In video coding, selecting an optimal intra block size based on minimal activity directions and strengths. The method is directed to simplifying the procedure of choosing the best subdivision of a texture block into intra blocks.

Claims

1. A method of choosing a best subdivision of a texture block into intra blocks in high efficiency video coding, the method comprising:

considering a texture block B having size L×

L and weight W and starting from a pixel with coordinates (x, y);

constructing four sub-blocks B_j, j ∈

[0,4] of size

2. The method of claim 1, wherein a minimal activity direction angle φ

(S, W) is calculated as a solution of a minimization problem;

3. The method of claim 2, wherein the minimal activity direction strengths are calculated as follows:

4. The method of claim 1, wherein S coincides with B, and S_j coincides with B_j.

5. The method of claim 1, wherein the pre-defined parameters λ

₁, μ

₁, λ

₂, μ

₂ are selected according to desired speed and quality of encoding.

6. A video codec comprising a control circuit configured and arranged to carry out a function of optimally dividing a texture block into a plurality of intra blocks by:

considering a texture block B having size L×

L and weight W and starting from a pixel with coordinates (x, y);

constructing four sub-blocks B_j, j ∈

[0,4] of size

7. The video codec of claim 6, wherein the minimal activity direction angle φ

(S, W) is calculated as a solution of a minimization problem;

8. The video codec of claim 6, wherein the pre-defined parameters λ

₁, μ

₁, λ

₂, μ

₂ are selected according to a desired speed of the video codec and to desired quality of encoding.