基于非线性提升小波变换的图像去噪

基于提升方案的小波变换结构简单 ,不需要额外的存储空间 ,易于实现。同时 ,提升方案中的预测和更新算子既可以是线性的 ,也可以是非线性的 ,这就为我们构造非线性小波提供了一条有效的途径。该文利用一些简单的非线性算子 ,如求中位数和最大值等 ,构造出基于整数的非线性提升小波 ,并将该方法应用于阈值去噪处理中 ,得到了较好的效果 ,明显提高了图像的信噪比

Image De- noising Based on Non- linear Lifting Wavelet Transform

Wavelet transform based on lifting scheme has a simple structure, needs no more storage space and is very easy to be implemented. Meanwhile, as the operations in the prediction and update steps of the lifting scheme can be linear as well as non-linear, it provides us an efficient way to construct non-linear lifting wavelet transforms. In this paper, we construct a series of non-linear integer wavelet transforms based on lifting scheme using some simple non-linear operations such as median, max and so on, which is extremely easy to be implemented. Then we apply some wavelet transform into image de-noising by thresholding and get a good result of this method for improving images' SNR remarkably.