A ring Re, (M) iff each nonzero homomorphicimage of R either contains a nonzero M-ideal or has an essential ideal.
一个环R∈（M）当且仅当R的每一个非零同态象或者包含一个非零M理想或者有本质理想。
2
The method of the fusion with the original image is presented on the basis of homomorphic filter, and realized it.
在同态滤波的基础上提出并完成了融合的去云的方法，并完成了方法实现。
3
Image preprocessing: the image is processed by several algorithms including gray level stretch, homomorphic processing and image smoothing, and then the quality of image gets better.