The ast.zero_snr_low parameter gives the value (in the range 0.0 to 1.0) at which to threshold the smoothed mask specified by parameter "ast.zero_snr_fwhm" . If it is negative, the value is taken as the max smoothed value of a blob containing " ast.zero_snr_low" pixels. Thus a value of " -1.1" will cut at a height just sufficient to remove blobs of a single pixel form the mask. A value of " -2.1" would remove blobs of two pixels form the mask, etc. [-1.1]

MAKEMAP, CALCQU