With the development of science and technology,the scale of the data we got becomes larger and larger,and type of the data also becames more and more complex.The data have multi-storage format,the grayscale photos are often stored in matrix form,the color photos are stored in the form of third-order tensors,and the video data are the fourth-order tensor.Therefore,this paper regards practical application with video compression as the application background to research the fourth-order tensor decomposition.First,the relation between the special third-order symmetric tensor decomposition and tensor approximation problem is considered.We present the rank-1 decomposition method of the third-order symmetric tensor,based on the tensor best rank approximation problem.This problem is an important part in the field of tensor research.Based on the above new method,the best rank-1 approximation of the third-order symmetric tensor is given.Meanwhile,the upper bound of the conditional error is estimate.Secondly,we propose three third-order tensor decomposition methods based on different fourth-order tensor multiplications.(1)based on the matrix multiplication,the F-product of the fourth-order tensor is proposed.Using the definitions of the circulant matrix,the Discrete Fourier Transform and the Singular Value Decomposition,the fourth-order tensor decomposition is obtained based on the F-product,record as F-TD;(2)the TH-product of the fourth-order tensor is proposed,based on the t-product definition of third-order tensor.Using the t-svd of the third-order tensor and the TH-product,the fourth-order tensor decomposition is obtained,record as FT-SVD;(3)based on the Face-wise multipliers of third-order tensors,we define a new fourth-order tensor B-product.The fourth-order tensor decomposition are obtain,which can be degenerated into matrix singular value decomposition,denoted as B-TD.Based on the above theoretical work,the resolution accuracy and running time of the two methods of F-TD and FT-SVD are compared by calculating artificial data and large scale random data.The results show that the above two decomposition methods have high decomposition accuracy.For the B-TD method,an accurate formula for the compression ratio of fourth-order tensors and the video compression algorithm are given.At last,the compressed videos of monochrome videos and color videos are presented.The experiments show that the B-TD method is feasible and has good compression effect. |