SECTION./BACKGROUND
FIT/BACKGROUND outframe = inframe(s) [deg,it] [clp1,clpn] [skew] [outbck]
FIT/BACKGROUND outframe = inframe(s) [coef] [outbck]
FIT/BACKGROUND inframe(s) [deg,it] [clp1,clpn] [skew] [outbck]
FIT/BACKGROUND inframe(s) [coef] [outbck]
	compute 2-dim. polynomial fit of the background
SECTION./ELL1
FIT/ELL1 inframe outframe l_iso,h_iso x_cen,y_cen max_rad
	fit an ellips with respect to predefined center
SECTION./ELL2
FIT/ELL2 inframe pol_opt iso_tol iso_levels [center[ [radius] [sky_level]
	fit an ellips with respect to predefined center
SECTION./ELL3
FIT/ELL3 inframe outframe [step] [x,y] [low,high] [min,max] [opt]
	fit ellipses to the isophotes of an object in a 2-dim. frame
SECTION./POSI
FIT/POSINC infram orient rin,rout,rstep region
	fit the position angle and inclination to 2nd and 4th harmonic
