input,s,a,,,,Input images
output,s,a,,,,Output image
title,s,h,"",,,Title for output image
hparams,s,h,"",,,List of header parameters
pixtype,s,h,"",,,Pixel datatype of output image
calctype,s,h,"",,,Calculation type
option,s,h,"sum","sum|average|median",,Output option
low_reject,r,h,0,,,Fraction or number of low pixels to reject
high_reject,r,h,0,,,Fraction or number of high pixels to reject
verbose,b,h,no,,,Print log of operation?