Reduction of code lines

Alright, so I've written this particular thing to blur an image and I've been wondering if I could reduce the number of lines or perhaps cut down the redundancies within this code especially the last line which copies one matrix to an other. Any over the top ideas would also be appreciated!

a=512;
b = a^2/16; 
c=(sqrt(b)-1)/2;  
ft11 = fftshift(fft2(myImage)); 
width = size(myImage,1); 
F1 = zeros(width);  
d = width/2; 
e = (d-c:d+c)+1;
ft11(e,e)=F1(e,e);

Answer 1

[Walter Roberson]

a = 512;
B = a/4; 
c = (B-1)/2;  
ft11 = fftshift(fft2(myImage)); 
width = size(myImage,1);
d = width/2; 
e = (d-c:d+c)+1;
ft11(e,e) = 0;

Answer 2

[Amit]

Its a good code. The only place I think there is a chance is

a=512;
b = a^2/16; 
c=(sqrt(b)-1)/2;  
ft11 = fftshift(fft2(myImage)); 
width = size(myImage,1); 
%F1 = zeros(width);  % You dont need to store these zeros
d = width/2; 
e = (d-c:d+c)+1;
ft11(e,e)=zeros(e);

[Amit]

you might think of putting (d-c:d+c)+1 directly. However this might create more overhead, due to temporary storing those values (3 times). (I might be wrong about this)