1. Instructor: Professor Yu Hen Hu
An Investigation of Hardware Implementation for Block Based Motion-Estimation Algorithm.
ECE734/Spring 2002
Instructor: Professor Yu Hen Hu By
Sarawadee Krepanith

2. Motivation
The main purpose of video coding is to reduce the bit rate by removing the redundant information
DCT for the reduction of spatial redundancy
Block-based motion compensation for the reduction of temporal redundancy

3. Block Matching Algorithm
Full search based block matching method is computationally very expensive, but give fairly accurate results.
There are others search methods that propose which are faster at the expense of accuracy. Examples are three step search, 2-D logarithmic search, the conjugate search, etc.

4. Three-Step Hierarchical Search
Find a best matched displaced block from the previous frame Ft-1 within the search range for each NxN block in the present frame Ft
In Full Search, matched all possible candidates exhaustively to find the motion vector with minimal distortion
Mean Absolute Difference (MAD) is used as criteria

5. Three-Step Hierarchical Search
Search for the best motion vector in the coarse-to-fine manner
First step, nine candidates are evaluated
Second and third steps, the distances between candidates are shortened

6. Challenging
Motion estimation is the bottleneck step in video coding as it requires most processing power
Many hardware implementations have been proposed
Comparison in various aspect will be delivered