sir, i m doing object follower robot .It follows only red ball, I run the following code in matlab

This code only display 'stop moving' on command window. and no detection of the ball takes place.so please give me solution of this.

I didn't understand color thresholding command use in this program and I don't understand calculation of e ?

code :-

clear;
clc % Clearing Matlab desktop
vid=videoinput('winvideo',1,'RGB24_640X480'); % Defining the video input object
set(vid,'FramesPerTrigger',1); % Setting frames per trigger
preview(vid); %////// Showing the video of the moving Ball(TO BE USED %
% WHILE TESTING)
pause(10);% Waiting for a certain time for the system to get initialised
rgb_image = getsnapshot(vid); % Storing Image in an array variable 
[a b c]= size(rgb_image); % Determining the size of the captured frame.
y=a;
x=b;

% Defining Boundaries 
x1=x/2-120;
x2=x/2+120;
y1=y/2-30;
y2=y/2+30;
ser=serial('COM34'); % Defining the specified COM Port to be used
fopen(ser); % starting serial Communication,opening serial port

while(1)
rgb_image = getsnapshot(vid); % storing image in an array variable 
flushdata(vid); %Flushing the buffer
rbar=0;
cbar=0;
e=0; 
fR=rgb_image(:,:,1);fG=rgb_image(:,:,2);fB=rgb_ima ge(:,:,3);% Storing RGB components of the image in seperate arrays
I=((fR<=70) & (fG>=80) & (fB<=70)); % Converting the RGB Image into binary image///Detecting only the red component
% Following are the steps For Detecting the red ball
se=strel('disk',20);
B=imopen(I,se);
final=imclose(B,se);
[L,n]=bwlabel(final);
%imshow(rgb_image); %////THIS IS TO BE USED ONLY WHILE TESTING
%hold on % ////THIS IS TO BE USED ONLY WHILE TESTING
for k=1:n
[r,c]=find(L==k);
rbar=mean(r);
cbar=mean(c);
%plot(cbar,rbar,'Marker','*','MarkerEdgeColor','B' ,'MarkerSize',20) %////THIS IS TO BE USED ONLY WHILE TESTING 
e=(((cbar>=x1)*2*2*2) + ((cbar<=x2)*2*2) + ((rbar>=y1)*2) + (rbar<=y2)) % Converting to decimal number
end
% Decision Making Conditions
switch (e)
case 5
disp('Move left'),fprintf(ser,'L');
case 6
disp('Move left'),fprintf(ser,'L');
case 7
disp('Move left'),fprintf(ser,'L');
case 9
disp('Move right'),fprintf(ser,'R');
case 10
disp('Move right'),fprintf(ser,'R');
case 11
disp('Move right'),fprintf(ser,'R');
case 13
disp('Move forward'),fprintf(ser,'F');
case 14
disp('Move back'),fprintf(ser,'B');
otherwise
disp('Stop Moving'),fprintf(ser,'S');
end
end
fclose(ser); % closing serial port

[Image Analyst]

Are you able to use the debugger to step through your code? If not, you definitely need to learn this indispensable skill - it's not hard.

[John D'Errico]

Did you write the code? If so, then how can you not understand what the variables are?

If you got the code from someone else, then ask the source.