Matlab - Filtrar imagen eliminando los puntos azules

%promedio

fid = fopen('cvv_ROAG_PTBB.dat');

d = textscan(fid,'%s %f %f');

fclose(fid);

nume = ((sin(d{2}(1)))^2)*(d{3}(1));

den = ((sin(d{2}(1)))^2);

long = length(d{2});

i=1;

j=1;

while (i < long)

  if (strcmp(d{1}(i),d{1}(i+1)) )

    i = i + 1;

    nume = nume + ((sin(d{2}(i)))^2)*(d{3}(i));

    den = den + ((sin(d{2}(i)))^2);

  else

    A(j,1) = nume/den;

    i = i + 1;

    j = j + 1;

    nume = ((sin(d{2}(i)))^2)*(d{3}(i));

    den = ((sin(d{2}(i)))^2);

  end

end

%promedio

fid = fopen('tw_roa_ptb.dat');

d_tw = textscan(fid,'%f %f');

fclose(fid);

x=d_tw{1};

y=d_tw{2};

x1=57204.011111111:0.0112:57234.927777778;

%filtrado8

filtered= smooth(A,500,'moving')

%grafica cv y tw

plot(x,y,'r.');

hold on

plot(x1',A,'b.');

hold on

plot(x1,filtered,'y-');

axis([57204.011111111 57234.927777778 -10 5]);