Howtosignalprocessing
- What is aliasing in imaging?
- What is aliasing in FFT?
- What does it mean for a signal to be aliased?
- How do you cause aliasing?
What is aliasing in imaging?
Sometimes called moiré or a glitch, aliasing is a phenomenon where a digital camera has trouble translating an intricate pattern. Aliasing can result in a number of odd visual artifacts in photos or videos.
What is aliasing in FFT?
Recognizing Aliasing in the FFT
It is common to have acquired signals with a fundamental frequency less than half the sample rate, but the harmonics of that signal may be greater than half the sample rate and they will alias. This shows up in the FFT as frequencies that fold back into the display.
What does it mean for a signal to be aliased?
Aliasing occurs when an oscilloscope does not sample the signal fast enough to construct an accurate waveform record. The signal frequency is misidentified, and the waveforms displayed on an oscilloscope become indistinguishable.
How do you cause aliasing?
Aliasing is Caused by Poor Sampling
A bandlimited signal is one with a highest frequency. The highest frequency is called the bandwidth ωb . If sample spacing is T, then sampling frequency is ωs =2π/T. (If samples are one pixel apart, then T=1).
