Dimension problem with Kirsch oprerator.

I just can't find the collision between formats in my vectors.Here's the code, basic kirsch operator in which I get error

"??? Assignment has more non-singleton rhs dimensions than non-singleton subscripts" in the for loop

function ks = Kirsch(A)

A = imread(A);

A = im2double(A);

m = zeros(3,3,8);
m(:,:,1) = [-3 -3 5; -3 0 5; -3 -3 5];
m(:,:,2) = [-3 5 5; -3 0 5; -3 -3 -3];
m(:,:,3) = [5 5 5; -3 0 -3; -3 -3 -3];
m(:,:,4) = [5 5 -3; 5 0 -3; -3 -3 -3];
m(:,:,5) = [5 -3 -3; 5 0 -3; 5 -3 -3];
m(:,:,6) = [-3 -3 -3; 5 0 -3; 5 5 -3];
m(:,:,7) = [-3 -3 -3; -3 0 -3; 5 5 5];
m(:,:,8) = [-3 -3 -3; -3 0 5; -3 5 5];

Am=zeros(size(A,1), size(A,2),8);
for i=1:8
    Am(:,:,i) = imfilter(A,m(:,:,i));
end

Ak = max(Am,[],3);

n = 255 / (max(Ak(:)) - min(Ak(:)));
pic = uint8(n * Ak);
figure, imshow(pic);

*********************************************************************************

error is in for loop where Am(:,:,i) = imfilter(A,m(:,:,i));

Please help, im looking into code for several hours, ive tried several source images, for loops etc, but error ist still here

Tomislav

[amit srivastava]

Hey, Can You tell me what you did after Ak..ASAP

Answer 1

[Matt J]

 A=rgb2gray(A); 

 Am(:,:,i) = imfilter(A,m(:,:,i),'same')