针对低信噪比图像去噪问题,提出了一种基于K-SVD(Singular Value Decomposition)和残差比(Residual Ratio Iteration Termination)的正交匹配追踪(Orthogonal Matching Pursuit,OMP)图像稀疏分解去噪算法。该算法利用K-SVD算法将离散余弦变换(Discrete cosine transform,DCT)框架产生的冗余字典训练成能够有效反映图像结构特征的超完备字典,以实现图像的有效表示。然后以残差比作为OMP算法迭代的终止条件来实现图像的去噪。实验表明,该算法相对于传统基于Symlets小波图像去噪、基于Contourlet变换的图像去噪,以及基于DCT冗余字典的稀疏表示图像去噪,能够更加有效地滤除低信噪比图像中的高斯白噪声,保留原图像的有用信息。
This paper addresses an improved distributed model predictive control(DMPC)scheme for multiagent systems with an attempt to improving its consistency.The deviation between what an agent is actually doing and what its neighbors believe that agent is doing is penalized in the cost function of each agent.At each sampling instant the compatibility constraint of each agent is set tighter than the previous sampling instant.Like the traditional approach,the performance cost is utilized as the Lyapunov function to prove closed-looped stability.The closed-loop stability is guaranteed if the weight matrix for deviation in the cost function are sufficiently large.The proposed distributed control scheme is formulated as quadratic programming with quadratic constraints.A numerical example is given to illustrate the effectiveness of the proposed scheme.
