horizontal Transition code error index out of bounds anyone help!!!

horizontal transition:

horizontal scanning thro block and finds no of times pixel value change state from 0 to 1 or 1 to 0

my coding :

[r c]=size(g);
for i=1:r-1
   for j=1:c-1;
       if(j==c)
          break;
       elseif  g(i,j)==0 && g(i,j+1)==1
        c=c+1;
       end
   end
end
disp(c);

and error is

Attempted to access g(213,1118); index out of bounds because size(g)=[1537,1117].

Error in ==> ht at 8
       elseif  g(i,j)==0 && g(i,j+1)==1

can anyone help to solve dis pls?

Answer 1

[Walter Roberson]

You could encounter that error if g has more than 2 dimensions.

By definition, if you use two output arguments, then

[r c] = size(g)

would be the same as

t = size(g);
r = t(1);
c = prod(t(2:end))

If for example, you had a 10 x 10 x 3 g matrix, then [r c] = size(g) would be r=10 and c=10*3

Of course other parts of your code are likely to have logical problems if g has more than 2 dimensions, but this size() problem is the way that you end up with the second dimension being out of range.

[priya]

g is binary image so tats not a prob ,size of image is 1117x1573. wen i perform j+1 in elseif statement , j taking value 1118(index out of bound) i ve to stop wen j is 1118 tat only my prob

[Walter Roberson]

Please show us the values of r and c as known to your program (that is, put in a breakpoint and see what the _program_ thinks they are.)

Answer 2

[priya]

    im=imread('');
g=rgb2gray(im);
[r c]=size(g);
c1=0;
for i=1:r-1
   for j=1:c-1
       if  g(i,j)==0 && g(i,j+1)==1
        c1=c1+1;
       end
   end
end
disp(c1);

[Walter Roberson]

That code would miss the last row, i==r .