We consider the class of (C4, diamond)-free graphs; graphs in this class do not contain a C4 or a diamond as an induced subgraph. We provide an efficient recognition algorithm for this class. We count the number of maximal cliques in a (C4, diamond)-free graph and the number of n-vertex, labeled (C4, diamond)-free graphs. We also give an efficient algorithm for finding a largest clique in the m...

In motion estimation, the search patterns with different shape and size have a large consequence on the searching speed and quality of performance. A popular example is the full search (FS) algorithm. Nevertheless, the high computational complexity of the FS algorithm has motivated several faster search strategies. However, the FS allows a better quality. In this paper, we compare the performan...

Many suboptimal motion vector search algorithms have been proposed because the full search algorithm, which is an optimal method, requires huge computational cost. Most of these algorithms find motion vectors simply from the center of the search window. In this paper, we propose an efficient motion vector search algorithm which, in order to predict the initial search point, exploits the global ...

A fast block motion estimation algorithm is proposed using modified diamond search patterns. This algorithm utilizes the directions and magnitudes of motion vectors between interblocks and uses a smaller number of search points than conventional diamond search patterns. Simulation results show that the proposed method significantly improves computational speed over other fast motion estimation ...

A fast block motion estimation algorithm is proposed using modified diamond search patterns. This algorithm utilises the directions and magnitudes of motion vectors between interblocks and uses a smaller number of seach points than conventional diamond search patterns. Simulation results show that the proposed method significantly improves computational speed over other fast motion estimation a...

In block motion estimation, a search pattern with a different shape or size has a very important impact on search speed and distortion performance. A square-shaped search pattern is commonly adopted in many popular fast algorithms. Recently, a diamond-shaped search pattern was introduced in fast block motion estimation, which has exhibited faster search speed. Based on an in-depth examination o...

This paper presents fast moving window algorithms for calculating local statistics in a diamond, hexagon, and general polygonal shaped windows of an image which is important for real-time applications. The algorithms for a diamond shaped window requires only seven or eight additions and subtractions per pixel. A fast sparse algorithm only needs four additions and subtractions for a sparse diamo...

We present new algorithms for finding induced four-node subgraphs in a given graph, which run in time roughly that of detecting a clique on three nodes (i.e., a triangle). • The best known algorithms for triangle finding in an nnode graph take O(nω ) time, where ω < 2.373 is the matrix multiplication exponent. We give a general randomized technique for finding any induced four-node subgraph, ex...

On the price of complexity, the new video compression standard H.264 is more effective than MPEG-4 in compression. Aimed at the motion estimation problem in search rate, a directional search pattern and an improved cross diamond search algorithm which adopts many technologies including prediction of initial search point, suitable search pattern choosing and auxiliary search points are proposed ...