It could be. Who's to say? It's more or less of a judgement call as to what amount of smoothing is best, isn't it. You could determine the sum of absolute differences for different window sizes and plot it. Maybe some pattern will jump out at you, like a knee in the curve.
clc; % Clear the command window.
close all; % Close all figures (except those of imtool.)
clear; % Erase all existing variables. Or clearvars if you want.
workspace; % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 20;
numPoints = 5000;
noiseSignal = rand(1, numPoints);
x = linspace(0, 300, numPoints);
period = 100;
cleanSignal = cos(2*pi*x / period);
noisySignal = cleanSignal + noiseSignal;
subplot(2, 1, 1);
plot(x, noisySignal, 'b-', 'LineWidth', 2);
grid on;
xlabel('x', 'FontSize', fontSize);
ylabel('Noisy Signal', 'FontSize', fontSize);
windowSizes = 3 : 3 : 51
for k = 1 : length(windowSizes)
smoothedSignal = movmean(noisySignal, windowSizes(k));
sad(k) = sum(abs(smoothedSignal - noisySignal))
end
subplot(2, 1, 2);
plot(windowSizes, sad, 'b*-', 'LineWidth', 2);
grid on;
xlabel('Window Size', 'FontSize', fontSize);
ylabel('SAD', 'FontSize', fontSize);
Pick the smallest window size where the SAD seems to start to flatten out. Going beyond that (to larger window sizes) really doesn't produce much more benefit (smoothing) and will take longer.
