How to program a Band-stop filter

Question

2.00/5 (2 votes)

See more:

hello
I've got an Image processing homework and need help
I've got a noisy camera man photo
when I used fft transform to know exactly where the noise is located I found it like a circle so I have to filter the image using a band-stop filter
my code in matlab is:
i = imread('D:/MY UNIVERSITY/FIFTH/IMAGE PROCESSING/practical/homework/9.jpg');
i=im2double(i);
i1 = fft2(i);
i2 = fftshift(i1);
figure,imshow(log(1+abs(i2)),[]);
[x,y]=meshgrid(-128:127,-128:127);
z=sqrt(x.^2+y.^2);
c = (z<30 & z>40);
c1 = fft2(c);
c2 = fftshift(c1);
figure,imshow(log(1+abs(c2)),[]);
cm = c2.*i2;
cm1=ifft2(cm);
figure,imshow(log(1+abs(cm1)),[]);

but it didn't work, when I showed the filter photo it was totally black and it isn't what I need to filter the image
Is it wrong what I did
any help will be appreciated

Posted 25-Dec-14 3:22am

Mujeeba Haj Najeeb

Add a Solution

Comments

Sergey Alexandrovich Kryukov 25-Dec-14 12:19pm

Maybe the only really wrong thing is that you did not try to troubleshoot the solution? :-)
—SA

Mujeeba Haj Najeeb 25-Dec-14 13:23pm

What do you really mean by saying I didn't try to troubleshoot the solution, I've been working on this problem for three days

Sergey Alexandrovich Kryukov 25-Dec-14 15:04pm

I said "maybe". Did you really use the debugger, etc..?
—SA

Mujeeba Haj Najeeb 25-Dec-14 15:23pm

Yes, I did every thing, as you see in code I used imshow instruction in every step and the result of the filter was totally black(without any pass areas)

Sergey Alexandrovich Kryukov 25-Dec-14 16:29pm

Right...
—SA

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Mujeeba Haj Najeeb · Answer 1 · 2014-12-26T03:21:00

Solution 1

finally I've solved it
the error was there is no reason to make fourier transform to the filter
thanks for time you gave to help

Posted 26-Dec-14 3:21am

Mujeeba Haj Najeeb