If it's possible to get the input values of the plot function you should extract the green points from there. Please post the Matlab code lines that plotted this figure. Using an image as input to get points is not where Matlab is good at.

@ Daniel, thanks for your kind reply..

Here is the code...

clc;

clear all;

close all;

f1=300

R_free_space = 1:1:800;

c=300000000;

lp_freespace1 =((4*pi*R_free_space*f1*10^6)/c).^2

temp1 = 20*log10(10^6)-20*log10(lp_freespace1);

%let us take circle of unit radius

R=R_free_space(min(find(temp1

If the coordinates are in these vectors, you just have to:

x =size(X(inside));

y =size(Y(inside));

if x == y

disp('vector x is as big as vector y')

else

disp('Error. check input vectors.')

end

green = zeros(x);

for i=1:x(1)

green(i,1) = X(i);

green(i,2) = Y(i);

end

You can try using the ginput function:

http://www.mathworks.com/help/matlab/ref/ginput.html