SECTION./FCOE COMPUTE/FCOEFF infram orient rin,rout,rstep outtab compute fourier coefficients of azimuthal profiles in spiral galaxies SECTION./GRID COMPUTE/GRID angle create image and table with distorted rect. and evenly spaced grid SECTION./COMP COMPUTE/SKY infram1 infram2 caltab method sky_factor compute the sky background and restitute the frame