Høyfrekventfiltrering

Høyfrekventfiltrering, also known as high-pass filtering, is a signal processing technique used to remove lower frequencies from a signal while allowing higher frequencies to pass through. This is achieved using a high-pass filter, which is an electronic circuit or digital algorithm designed to attenuate or block signals below a certain cutoff frequency. Frequencies above this cutoff are passed through with minimal attenuation.

The primary application of high-pass filtering is to isolate or emphasize high-frequency components of a signal. This can be useful in various fields. In audio processing, for example, high-pass filters are used to remove unwanted low-frequency noise like hum or rumble, or to shape the tonal characteristics of instruments by reducing muddiness. In image processing, high-pass filtering can be employed to sharpen images by enhancing edges and details, which are essentially high-frequency spatial variations.

The design of a high-pass filter is characterized by its cutoff frequency, which defines the transition point between the passband (frequencies that are allowed to pass) and the stopband (frequencies that are attenuated). The steepness of this transition is determined by the filter's order or slope. Higher-order filters provide a sharper cutoff, leading to more effective separation of frequencies. High-pass filters can be implemented using passive components like resistors and capacitors, or active components like operational amplifiers. In digital signal processing, they are implemented as algorithms operating on sampled data.