The clustering problem under the criterion of minimum sum of squares is a non-convex and non-linear program, which possesses many locally optimal values, resulting that its solution often falls into these trap and therefore cannot converge to global optima solution. In this paper, an efficient hybrid optimization algorithm is developed for solving this problem, called Tabu-KM. It gathers the ...

Quaternion non-local means (QNLM) denoising algorithm makes full use of high degree self-similarities inside images to suppress the noise, so similarity metric plays a key role in its performance. In this study, two improvements have been made for QNLM: 1) For low level quaternion quasi-Chebyshev distance is proposed measure image patches and it has used replace Euclidean QNLM algorithm. Since ...