[Matlab] Constructing a 3d histogram from a picture

I wrote a function for constructing histogram for an arbitrary picture. It reads only R (red) and G(green) channel.

Code:

`function H = myhistogram2RG(img1, bins)`

%Here you make eqaul distribution for the pixels

img1 = floor(double(img1)*(bins) / 255 ) + 1 ;

%Matrice bins * bins all of zeroes

H = zeros(bins, bins);

for i=1:size(img1, 1)

for j = 1:size(img1, 2)

R = img1(i,j,1);

G = img1(i,j,2);

%When the pixel is the right colour add one to corresponding

%element in the matrice

H(R,G) = H(R,G) + 1;

end

end

%Normalization

H = H / sum(sum(H));

end

When I read a picture with imread command, and I call a function with myhistogram2RG(image,10) I get an error.

Code:

`Attempted to access H(11,8); index out of bounds because`

size(H)=[10,10].

I don't understand why isn't working. Thank you for your help.