DFT: Filtering in the Frequency Domain I

Building the Cantata Workspace

1. Create a vertical binary image using a sinusoidal signal in the width direction, followed by a comparison opertator to threshod, and display the result. Use the operators Sinusoidal, >= and Display Image.
2. Use operators Low-Pass, High-Pass, and Band-Pass to design "ideal" filters. Display the filters.
3. Take the forward Fourier transform of the image and multiply it by each filter. Use operators FFT and Multiply.
4. Display each magnitude spectrum after it has been filtered.
5. Take the inverse Fourier transform and display the real part of it. Use operators FFT and Real Part.

Exercises

• Perform the same experiment with different parameters (diameters) for the "ideal" filters.
• Design non-ideal filters (Butterworth, Exponential, Chebyshev I, and Chebyshev II) and repeat the experiment. Experiment with the order of a filter and the cut-off parameters.