Hi i am getting Index out of bounds error pls help me solve it

I hv a 2d image of 93×58 pixels. Error im gettin is attempted to access b(1,59) because size(b)=(93,58).

How do i go about rectifying this error?? Pls help as im new to matlab and to image processing. Thanks in advance.

[Serena Woolridge]

Hi i understand that i im attempting to get a 59th column but i would like to know how i can change my code to rectify it.Pls help.

my code goes like..

    for ii=1:m2
        for jj=1:n2
        x=(b(ii,jj) /100)*(mapsize*mapsize);
        end
    end

[Serena Woolridge]

To make it more clear, i am attempting to split pixels into subpixels of my image of size(93x58) and assign 1s and 0s to the subpixels in order to classify my image into its various classes. The error keeps appearing in the loc:

 x=(b(ii,jj)/100)*(ms*ms);

The code i use is:

a=imread('image path');

imshow(a);

[m1,n1,o1]=size(a);

ms=input('enter map size');

m2=m1*ms;

n2=n1*ms;

     for ii=1:m2
       for jj=1:n2
        x=(b(ii,jj)/100)*(ms*ms);
        x=round(x);
      if(x==(ms*ms))
        for n=1:(ms*ms)
        mat(n)=1;
        end
       else
          r=randi(1,ms*ms,ms*ms);
          d=magic(ms);
           for n=1:x
              mat(d(n))=1;
           end
           for n=x+1:(ms*ms)
              mat(d(n))=0;
           end
        end
 end

Please help me clear this error in order for me to do my project work. Thanks in advance.

Answer 1

[Star Strider]

You’re asking for column 59 of a 58-column matrix.

Think about it ...

EDIT — Seeing only the part of your code that you posted (about 8 hours ago), I would simply reverse the values of ‘m2’ and ‘n2’ in your loops.

[Serena Woolridge]

Thanks, i have tried reversing the values but i get the same error. Is ther any other way to clear this?..

[Star Strider]

In these lines:

m2 = m1*ms;
n2 = n1*ms;

the ‘ms’ variable has to be greater than 0 and less than or equal to 1 for that to work correctly.

The only way I can come up with to avoid addressing outside the dimensions of your image is with something like this:

m2 = fix(max(1,m2));
m2 = fix(min(m1,m2));
n2 = fix(max(1,n2));
n2 = fix(min(n1,n2));

That limits the index variables to the limits of your image size.

Answer 2

[MHN]

So, you should not attempt to get b(1,59) when the size of b is (93,58) !!!

Answer 3

[Walter Roberson]

Consider the possibility that you have m2 and n2 exchanged in your code.

Another possibility: did you use

[m2, n2] = size(YourMatrix)

and your image is a color image? If so then you have a bug because of the way that size() is defined when you have fewer outputs than the array has dimensions. Instead use

[m2, n2, ~] = size(YourMatrix)

[Serena Woolridge]

Thanks, i have tried both the alternatives provided by you but the same error keeps appearing. Is there any other method that can be done to clear this error?? thanks in advance.

[Walter Roberson]

We need to see your code.