nsst域内基于区域能量和区域方差取最大值的图像融合算法，简单易懂。主程序高频区域能量取大，低频加权平均，读者可自行修改。-nsst maximum value within an image fusion algorithm based on regional energy and regional variance, easy to understand. Main high-frequency energy to take large area, low-weighted average, readers can modify.