In the CLEAN variant proposed by (), extended features (instead of point sources) around the current maximum of the residual map are selected and removed in a single step. The simplest implementation redefines the notion of minor and major cycles of the CLARK algorithm. In the minor cycles, only the selection of the clean components is done by including all the pixels in the residual map that rise above a contour set at some fraction of the current peak level. In major cycles, all those components are removed together in the Fourier plane. The SDI algorithm may be instable is the fraction used for the selection of clean components is badly chosen.