images,s,a,,,,"Images"
masks,s,h,"",,,"Masks"
groups,s,h,"*",,,"Range of groups"
g_accum,b,h,no,,,"Accumulate over groups?"
fields,s,h,"npix,mean,stddev,min,max",,,"Fields to be printed"
lower,r,h,INDEF,,,"Lower cutoff for pixel values"
upper,r,h,INDEF,,,"Upper cutoff for pixel values"
gstpar,pset,h,,,,"Results of statistics on the last image (pset)"