Gabor Filter

I am trying to execute gabor filter on images.

{%%Read  clear all; 
close all;
clc; 
I=imread('test.png'); 
imshow(I); 
%%Crop I2 = imcrop(I); 
figure, imshow(I2) 
m=size(I2,1); 
n=size(I2,2); 
%%Gabor 
phi = 7*pi/8; 
theta = 2; 
sigma = 0.65*theta;
for i=1:3  
 for j=1:3 
      xprime= j*cos(phi); 
      yprime= i*sin(phi);   
    K = exp(2*pi*theta*i(xprime+ yprime)); 
      G= exp(-(i.^2+j.^2)/(sigma^2)).*abs(K);   
end 
end 
%%Convolve 
for i=1:m   
for j=1:n  
    J(i,j)=conv2(I2,G);   
end 
end 
imshow(uint8(J)) 
I am getting this error always.  
 ??? Subscript indices must either be real positive integers or logicals. 
Not sure how to solve this...

Answer 1

[Walter Roberson]

You have

K = exp(2*pi*theta*i(xprime+ yprime));

which attempts to subscript your variable "i" at the index "xprime + yprime". Perhaps you wanted i*(xprime + yprime) ?

[C N N]

thanks. but after i corrected that i had another error.

??? Subscripted assignment dimension mismatch.

Any idea?