When grid filters encounter unusual inputs, they tend to pass them unchanged. Grid filters can detect and flag regions of images which are unlike the training images. Certain types of grid filters contain order statistic filters as a subset. Hybrid grid filters contain Lee's local statistics filter for additive noise as a special case. In practice, the performance of grid filters is superior to order statistic filters, Lee's filter, and the global Wiener filter.
Preliminary results are tantalizingly good.
Grid filters are able to exploit structural characteristics of images to achieve excellent results for both noise suppression and superresolution.