i'm working with image ,i cant load 512*512 image

all time i face a error

Attempted to access N(1,1,3); index out of bounds because size(N)=[256,256,1].my code is here:

function [mg_length,mes] = embed_file(image_file1,text_file1)

clc

M=imread(image_file1); [X,Y,V] = size(M);

disp(sprintf('%d %d %d',X,Y,V));

%N=rgb2gray(M);

N=M;

T=N;

str={};

z='';

count=0;

fid = fopen(text_file1);

tline = fgetl(fid);

while ischar(tline)

      if(length(tline)==0)

          z=[z,char(dec2bin(13,8))];

          z=[z,char(dec2bin(10,8))];

      else

          str=[str,tline];
          t= dbinary(str);
          if(count~=0)
              z=[z,char(dec2bin(13,8))];
              z=[z,char(dec2bin(10,8))];
          end
          z=[z,t];

      end

     count=count+1;
     tline = fgetl(fid);
     str='';
  end

mes='';

disp(z); %disp(N);

imageSize=X*Y;

key=length(z);

mg_length=key;

disp('message length');

disp(key);

if(imageSize>key)

mes='embed successful';

d=1;

for i=1:X

      for j=1:Y

          a=N(i,j,3);

          b=z(1,d);

         [T(i,j,3),p]=changeImage2(a,b,key);

         %a=N(i,j,2);

         %[T(i,j,2),p]=changeImage2(a,b,length_Z);

         %a=N(i,j,3);

         %[T(i,j,3),p]=changeImage2(a,b,length_Z);

         if(d==key)
             break;
         end
         if(p==1)
          d=d+1;
         end
      end
      if(d==key)
          break;
      end

end

how can i fix it ?

Answer 1

[Geoff Hayes]

Farjana - the error message is occurring because of the line of code

 a=N(i,j,3);

which is trying to access the third dimension of the matrix N when it only has two dimensions (your input image is grayscale, 256x256, and not colour, 256x256x3). Either change the line of code to

 a=N(i,j);

or select a colour image.

[Farjana Yeasmin]

but i can not fix the problem.. would you plz suggest me that how can i load image in all sizes in my code ?

[Geoff Hayes]

Why is the reason that you are using this line of code

 a=N(i,j,3);

Why not use

 a=N(i,j,1);

instead?

[Image Analyst]

Farjana, the code was meant for color images. Since you have grayscale images, you commented out the color part but that's not all you need to do. You need to change the line of code that Geoff told you to. You probably also want to change T(i,j,3) to T(i,j).

[Farjana Yeasmin]

ok.. got a solution .. thank you