... In asmooth at present sources can be removed and the local background interpolated over their positions. ... To create such a map, the user should supply asmooth , via the parameters withsrclistset and srclistset , with a list of sources produced by either eboxdetect or emldetect . ... For each source, asmooth calculates an elliptical boundary, being the locus at which the point spread function (PSF) of the source decreases to some constant value times the value of the local background. ...