Clouds Motion Estimation from Ground-Based Sky Camera and Satellite Images

Estimation of cloud motion is a challenging task due to the non-linear phenomena of cloud formation and deformation. Satellite images processing is a popular tool used to study the characteristics of clouds which constitute major factors in forecasting the meteorological parameters. Due to the low resolution of satellite images, researchers have turned towards analyzing the high-resolution images captured by ground-based sky cameras. The first objective of this chapter is to demonstrate the different techniques used to estimate clouds motion and to compare them with respect to the accuracy and the computational time. The second aim is to propose a fast and efficient block matching technique based on combining the two types of images. The first idea of our approach is to analyze the low-resolution satellite images to detect the direction of motion. Then, the direction is used to orient the search process to estimate the optimal motion vectors from the high-resolution ground-based sky images. The second idea of our method is to use the entropy technique to find the optimal block sizes. The third idea is to imply an adaptive cost function to perform the matching process. The comparative study demonstrates the high performance of the proposed method with regards to the robustness, the accuracy and the computation time

A Potential Heuristic-based Block Matching Algorithms for Motion Estimation in Video Compression

Motion estimation (ME) is one of the element keys in video compression that takes up to 60% in processing time. Block matching algorithm (BMA) is a technique that is used to reduce the computational complexity of ME algorithm due to its efficiency and good performance. Strategy of searching is one of the factors in developing motion estimation algorithm that has the potential to provide good performance. This study aims to implement several selected BMAs for achieving the least number of computations and to give better Peak Signal to Noise Ratio (PSNR) values using different video sequences. The proposed algorithms are modified based on the search strategy adapted from the standard algorithms approach. The results have proved that both modification algorithms (MDS and MARPS) have the potential in reducing the number of computations and achieved good PSNR values in all motion types as compared to DS and ARPS respectively. This work could be improved by using metaheuristic algorithms approach such as particle swarm optimization (PSO), artificial bee colony (ABC), tabu search (TS) and etc to provide the better result of PSNR values without increasing the number of computation