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

reference frame current frame motion vector residual Introduction

Introduction remove the temporal redundancy switch FBMA among the motion contents A-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)

Block-Base Gradient Descent Search (BBGDS)

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)

NTSS

FSS

Algorithm with minimum computation

Search Pattern Utilized

Outline Basic Methods Predicted Profit List A-TDB Algorithm Results References

Predicted Profit List Initial ： 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

the 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 T i 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 (T c ) What does the cleanup phase do? ◦ skip the remaining blocks in the profit list ◦ A-TDB stops

test sequences

the effect of T i

the value of T i is negligible

the effect of T a

2, 3, and 4 are good choices for Ta

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