韋弘 2010-07-05

Adaptive Fast Block-Matching Algorithm by Switching Search Patterns for Sequences With Wide-Range Motion Content

韋弘 2010-07-05

reference frame current frame

motion vector residual

Introduction

Introduction

remove the temporal redundancy

switch FBMA among the motion contentsA-TDB algorithm based on predicted

profit list

Outline

Basic Methods

Predicted Profit List

A-TDB Algorithm

Results

References

Outline

Basic Methods

Predicted Profit List

A-TDB Algorithm

Results

References

motion vector

Full search

Three-Step Search (TSS)

Three-Step Search (TSS)

Block-Base Gradient Descent Search(BBGDS)

Block-Base Gradient Descent Search(BBGDS)

Diamond Search (DS)

Diamond Search (DS)

Fast Block-Matching Algorithm

three-step search (TSS)

new three-step search (NTSS)

block-based gradient descent

search (BBGDS)

diamond search (DS)

four-step search (FSS)

Algorithm with minimum computation

Search Pattern Utilized

Outline

Basic Methods

Predicted Profit List

A-TDB Algorithm

Results

References

Predicted Profit ListInitial：MSE(profit) at (0,0)a sorted list of blocks in

descending order of profit

Characteristics(1/4)the distribution of the profits is not

uniform

Characteristics(2/4)the blocks usually include several

various motion contents

Characteristics(3/4)the MVs of the neighboring blocks

are strongly correlated

Characteristics(4/4)the MV is very likely to be zero near

the end

Outline

Basic Methods

Predicted Profit List

A-TDB Algorithm

Results

References

A-TDB Algorithm

Initialization Phase

Initialization Phasethe other objective

◦determine the initial rate of motion in the adaptive zone (based on MVs)

◦MV(length) > (¼)x(search range) => rapid◦MV(length) 1 => slow

if successive Ti blocks have rapid (moderate or slow)

=> change to adaptive phase

Adaptive Phase

Cleanup Phase

When does A-TDB change to the cleanup phase?

◦ predicted profits of the blocks < threshold (predefined)

◦ the MVs found are consecutive zero (Tc)

What does the cleanup phase do?

◦skip the remaining blocks in the profit list

◦A-TDB stops

test sequences

the effect of Ti

the effect of Ti

the value of Ti is negligible

the effect of Ta

the effect of Ta

2, 3, and 4 are good choices for Ta

the effect of Tc (>6)

Outline

Basic Methods

Predicted Profit List

A-TDB Algorithm

Results

References

Result

Result

Result

Outline

Basic Methods

Predicted Profit List

A-TDB Algorithm

Results

References

References [1]S.-Y. Huang, C.-Y. Cho, and J.-S. Wang, “Adaptive fast block-matching

algorithm by switching search patterns for sequences with wide-range motion content”, IEEE Trans. Circuits and Systems for Video Technology , vol. 15, no. 11, p.p.1373-1384, Nov. 2005.

[2] L. K. Liu and E. Peig, “A block-based gradient descent search algorithm for block motion estimation in video coding,” IEEE Trans. Circuits Syst. Video Technol., vol. 6, no. 8, pp. 419–423, Aug. 1996.

[3] S. Zhu and K.-K. Ma, “A new diamond search algorithm for fast block matching motion estimation,” IEEE Trans. Image Process., vol. 9, no. 2, pp. 287–290, Feb. 2000.

[4] A. Andersson, T. Hagerup, S. Nilsson, and R. Raman, “Sorting in linear time,” J. Comput. Syst. Sci., vol. 57, pp. 74–93, 1998.