Lesson 5 - Discrete Fourier Transform
This lesson demonstrates discrete fourier transforms using VisiQuest:
A Pulse Example | 2D DFT from 1D DFT | Properties | Simple Images | Pulse Width and Zero-Crossings | Sample and Aliasing | Filtering in the Frequency Domain | Filtering of Coherent Noise
Each section takes you through an incremental portion of the lesson while building on skills learned in previous lessons and sections.
Section 1 - DFT: A Pulse Example
Use the Discrete Fourier Transform with a 1D signal.
Section 2 - 2D DFT from 1D DFT
Demonstration of 2D Discrete Fourier Transform concepts using 1D DFT.
Overview of Rotation, Linear Combination, Translation, and Expansion as properties of DFT.
Section 4 - DFT: Simple Images
View DFT against several simple images.
Section 5 - DFT: Pulse Width and Zero-Crossings (Bandwidth)
View the relationship between pulse width in one domain and zero-crossings in the other.
Section 6 - DFT: Sampling and Aliasing
Visualize the concepts of sampling and aliasing effects.
Section 7 - DFT: Filtering in the Frequency Domain
Select which cosine waveforms (primitives) pass through the filter and which get attenuated.
Section 8 - DFT: Filtering of Coherent Noise
Remove noise from an image.