[correct] = fir2fix(n, m);
Correction for MTF of derivative (difference) filter
n = frequency data length [0-half-sampling (Nyquist) frequency]
m = length of difference filter
e.g. 2-point difference m=2
3-point difference m=3
correct = nx1 MTF correction array (limited to a maximum of 10)
Example plotted as the MTF (inverse of the correction)
% 2-point
[correct2] = fir2fix(50, 2);
% 3-point
[correct3] = fir2fix(50, 3);
figure,plot(1./correct2), hold on
plot(1./correct3,'--')
legend('2 point','3 point')
xlabel('Frequency index [0-half-sampling]');
ylabel('MTF');
axis([0 length(correct) 0 1])
24 July 2009
Copyright (c) Peter D. Burns 2005-2009