The CLEAN algorithm is a computational algorithm to perform a deconvolution on images created in radio astronomy. It was published by Jan Högbom in 1974 and several variations have been proposed since then.
The algorithm assumes that the image consists of a number of point sources. It will iteratively find the highest value in the image and subtract a small gain of this point source convolved with the point spread function ("dirty beam") of the observation, until the highest value is smaller than some threshold.
References
CLEAN (algorithm) Wikipedia(Text) CC BY-SA