function [y] = f_compression(x, nbits_in, nbits_out, step)

% nonlinear transforms 

for i = 1:length(x),
     y(i) =  out_range * (2^(x(i) / in_range)- 1) ;
end;


subplot(221), stairs(x,y); title('Compression'); 

for i = 1:length(y),
    xb(i) = (in_range) * log2(1+y(i)/(out_range-1));
end;
subplot(222), stairs(y,xb,'r'); title('Expanding')

subplot(212), stairs(x, xb-x); 
title('Reconstruction Error: reconstructed - original');