%Dialog Box to browse and select image
[name path]=uigetfile({'*.jpg','IMAGE Files (*.jpg)'},'Choose Image for Thresholding');
A=imread(strcat(path,name));
%converting rgb to gray
A=rgb2gray(A);
for i=1:255
    figure(1),imshow(A,[i 255-i]);
    pause(0.01);
end