Adaptive Order Cross–Square–Hexagonal search and fuzzy tangential-weighted trade-off for H.264 in motion estimation

In recent years, various algorithms have been proposed to attain low computational complexity in motion estimation of the image sequence coding based on block matching. This paper presents an Adaptive Order Cross–Square–Hexagon (AOCSH) search algorithm, which employs a smaller cross-shaped pattern before the first step of a square pattern and replaces the square-shaped pattern with the hexagon search patterns in subsequent steps. The proposed search patterns aid in finding the best matching block, without much consideration of the vast number of search points. Here, fuzzy tangent-weighted function is also proposed to evaluate the matching points using the rate and the distortion parameters. The proposed methods are effectively applied to the block estimation process to handle the objectives of visual quality and distortion. The performance of the proposed AOCSH approach is compared to the existing methods, such as AOSH, H.264 and elastic models, using the structural similarity index (SSIM) and the peak signal to noise ratio (PSNR). From the analysis, it can be seen that the proposed approach attains the maximum SSIM of 0.99 and maximum PSNR of 40. 92 dB with reduced computation time of 3.28 s.