I was looking at this site and saw the term. While I'm a bit familiar with some DSP terminology, I have never heard of this before. Google did not really help at all.
From what the site explores, it seems like it's either a type of filter, like IIR or FIR filters, or an algorithm like the FFT. The site, however, does not focus on DSP but focuses on computer science.
Any ideas? Would it have something to do with thresholding?