No abstract

An adaptive region-segmentation based multi-focus image fusion method is presented using a Laplacian pyramid transform which decomposes the pre-registered source images into approximate and detail coefficients. In order to avoid the disadvantage of fixed-size blocks, the adaptive differential evolution scheme is designed to compute the optimal-size block. Firstly, with approximate coefficients, the optimal-size blocks are iteratively calculated by an adaptive differential evolution algorithm. The initial decision diagram is then completed by comparing the regional sum-modified Laplacian energy of two corresponding blocks after the regional sum-modified Laplacian energy is calculated. Secondly, the initial decision diagram is optimized by the guided image filter to obtain the final decision diagram in order to avoid the block effect of boundary. With the decision diagram, the approximate coefficients are fused using the weighted mean rules, while the detail coefficients are fused using the regional gradient energy method. Finally, an inverse Laplacian pyramid transform is used to reconstruct the fused approximate coefficients and fused detail coefficients, and to acquire the fused image where all objects are clear. The experimental result proves that the proposed method produces fusion images of fewer artifacts or additional noise, with higher computational efficiency. The proposed method is also superior to the other state-of-the-art methods in both subjective visual effect and objective quantitative evaluation indicators.

We study the normality of families of meromorphic functions related to a Hayman conjecture. We consider whether a family of meromorphic functionsℱis normal inDif, for every pair of functionsfandginℱ,f′−afnandg′−agnshare the valuebforn=1,2, and 3, whereaandb≠0are two finite complex numbers. Some examples show that the conditions in our results are the best possible.

Considering the series effects of high power microwave such as thermal fast electrons effect, collision frequency effect and ionization frequency effect, a unified high power microwave (HPM) propagation model is presented in this paper. A unified air-breakdown model for single-pulse HPM is discussed in detail and the breakdown threshold is determined. It is found that the frequency of plasma induced by high power microwave is greater than previous value. The threshold of air breakdown increases with altitude increasing under the same condition. When the threshold reaches a minimum, a reverse trend will appear. And the minimum value will be obtained in an area of 30-60 km. The typical phenomenon waveform and threshold are gained in the experiment of air breakdown in microwave darkroom. And a well uniform distribution of the air breakdown threshold is shown theoretically and experimentally.

No abstract