|
In this thesis, we propose two new fast search algorithms in
block motion estimation (BME) : the clustering search algorithm
(CSA) and the two-way search algorithm (2WS).Besides CSA and
2WS, we also propose a new block matching method, named the
dynamic-shaped block matching (DSBM), to achieve the better
image quality.Basically, CSA is a feature-base search algorithm.
It improves the search speed of BME by less calculated pixels
within each block. CSA selects the most representative pixels
of each block with the clustering technique, and refines the
final motion vector by the center-biased concept.2WS is a
position-base search algorithm. It improves the search speed
of BME by reducing the checked blocks of search window in
previous frame. 2WS does not only simply chooses two positions
in each step but also finds the motion direction between every
two steps. As for DSBM, it is a new block matching method whose
blocks in each frame of a video do not need to be square.
Moreover, all kinds of combinations of small blocks are taken
into consideration in DSBM.DSBM therefore provides a better
structure to get higher image quality in BME.
|