i am trying to make a highpass filter manually but error appears in line 6 saying " the operation or expression "(" has no evident effect " what can i do ?

 img=imread('cameraman.tif');
 ftrans=fft2(img);
 ftrans=fftshift(ftrans); 
%[m,n]= size(256,256); 
 highpassfilter=ones(256,256); 
 highpassfilter(128-30:128+30,128-30:128+30); 
 smoothed=ftrans.*highpassfilter;
 out=ifft2(smoothed);

Answer 1

[hmi amid]

Hi Ahmed, I think you should assign the values highpassfilter(128-30:128+30,128-30:128+30) to something. You are just outputting values of highpassfilter(128-30:128+30,128-30:128+30) into Ans which does not do anything. Maybe : highpassfilter(128-30:128+30,128-30:128+30)=0; ? Amid.

[Ahmed Eweed]

oh.. i didn't mind that, it worked. thanks a lot Amid :)