Guide for beginners: What is Aliasing?

Aliasing (important in 3D configurator projects) is an effect that causes different signals to become indistinguishable during sampling. Aliasing is characterized by the change in the output signal compared to the original signal, since resampling or interpolation results in a lower resolution in images, a slower frame rate with respect to video, or a lower wave resolution in audio. Anti-aliasing filters can be used to solve this problem.

In a digital image, aliasing manifests itself as a moire pattern or wave effect. This spatial aliasing in the pattern of the image makes it look like it has waves emanating from a certain area. This happens because the pixelation of the image is bad. When our eyes interpolate these pixels, they just don’t look good.

Aliasing can also occur in videos where it is called temporary aliasing because it is caused by the frequency of the frames and not by the pixelation of the image. Because of the limited frame rate, a fast-moving object looks like a wheel, as if it were turning backwards or too slowly, this is called a cartwheel effect. This is determined by the frame rate of the camera and can be avoided by using temporary aliasing reduction filters during filming.

In audio, aliasing is the result of sampling at a lower resolution, resulting in poor sound quality and static. This occurs when the sound is sampled at a lower resolution than the original recording. When converting the sinusoidal audio wave to a digital wave with a lower resolution sample, only a few specific points of the wave are taken as data. This results in a wave with a lower frequency than the original, resulting in a loss of data and audio quality.

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