image_plot(I,A,B)

%This function shows a matrix image and plots a straight line(defined by
%two points).
%The user is should be aware of the difference between the image 
%coordinates and the normal coordinates.
%      Inputs:          
%           I: an image matrix of dimension mxnx3 or mxn
%           A: 2x1 matrix of type double/First point of the straight line
%           B: 2x1 matrix of type double/Second point of the straight line
%   Example:   image_plot(I,[1,2],[3,4]);
%              
%This function is written by :
%                             Nassim Khaled
%                             American University of Beirut
%                             Research Assistant 
function image_plot(I,A,B)
imshow(I);
hold on
plot([A(1),B(1)],[A(2),B(2)])
plot([A(1),B(1)],[A(2),B(2)],'r*')
hold off