I have a cameraman (the built in one) image which is multiplied by an unknown cosine function. How can i remove the cosine function from the image in Frequency Domain?

Can I find the cosine using Euler's Formula i.e cos(jux)=1/2* (e^(jux) + e^(-jux)) where j= is imaginary part in the fft2, u= phase angle, x=row

Answer 1

[Image Analyst]

If you know where the ripples are, then you can just divide by the pure ripple pattern. If you don't know where the ripples are, then you need to do Fourier filtering. Lucky for you I already have a canned demo ready to go. It's attached below the image it creates.

[Ali Ahmad]

The solution you have submitted is for additive noise. The image has been multiplied with a cosine image. I have attached the Image and its fourier

[Ali Ahmad]

Sorry, yours was it was for multiplied image! I have a phase shift also in my image

[Image Analyst]

Right. Easily adapted. Feel free to take the code and adapt it to both the magnitude and phase images.

Additive periodic noise will have peaks/spikes in the Fourier domain just like the multiplicative noise. Just find those spikes and zero them out. Should be easy. Let me know if you can't figure it out. Otherwise if we're done then maybe you can "Accept this answer."

[Muhammad Hanif]

i do have the same problem can not understand how to deal with the phase shift?