1. A multi-band image fusion method, comprising: receiving three or more images, wherein each image includes a plurality of channel types, and wherein each image has at least one channel of each of the plurality of channel types; selecting one of the three or more images to serve as a reference image, wherein each of the other images not selected as the reference image is selected to serve as an input image; registering each of the input images to the reference image; applying multi-band noise reduction to the reference image to generate a filtered pyramidal representation of each of the reference image's channels, wherein the pyramidal representation of each of the reference image's channels comprises a plurality of levels; applying multi-band noise reduction to each input image to generate a filtered pyramidal representation of each channel of each input image, wherein the pyramidal representation of each channel of each input image comprises a plurality of levels; fusing, on a level-by-level basis, each of the reference image's filtered pyramidal representations with a corresponding filtered pyramidal representation of each input image to generate a fused image channel for each channel of the reference image; and saving the fused image channels to a memory.