The function removes X-ray spikes (very bright/dark spots) in images by applying a median filter (of given type & size) and comparing the original image with the filtered one. If the difference is larger than a certain limit (given as multiplicative factor of the standard deviation in of the difference image), the pixel value is replaced by the mean value. Else it remains unchanged. Works well and fast with TYPE=3 SIZE=1
This function should work similar to the Volume/Remove X-rays menu-command of Gatan, but I do not know what this packages does exactly.