radiance correction

[rich Bochkay]

help!!
Does anyone know how to enlighten the shaded areas of a satellite image?
I've tried dividing the original spectral response by a shade map generated by shade.rel.sh. 
The output of this equation is a map that is now shaded where it once was bright and bright where itonce was shaded. If anyone knows of an equation to generate a normalized spectral response, please let me know.
Thanks,
Rich Bochkay
bochkay at ocean.rutgers.edu