Temporal Filter

Summary

Doc_BoxAlgorithm_TemporalFilter.png
  • Plugin name : Temporal Filter
  • Version : 1.1
  • Author : Yann Renard & Laurent Bonnet
  • Company : Mensia Technologies SA
  • Short description : Temporal filtering based on various one-way IIR filter designs
  • Documentation template generation date : Nov 2 2017

Description

Applies a temporal filter, based on various one-way IIR filter designs, to the input stream.

This plugin is used to filter the input signal. This plugin allows the selection of the kinf of filter (Butterworth, Chebychev, Yule-Walker), the kind of filter (low-pass, high-pass, band-pass, band-stop), the low or/and the high edge of the filter, and the passband ripple for the Chebychev filter.

Inputs

1. Input signal

The input signal.

  • Type identifier : Signal (0x5ba36127, 0x195feae1)

Outputs

1. Output signal

The filtered signal.

  • Type identifier : Signal (0x5ba36127, 0x195feae1)

Settings

1. Filter Method

Select the name of filter between Butterworth, Chebychev and Yule-Walker.

  • Type identifier : Filter method (0x2f2c606c, 0x8512ed68)
  • Default value : [ Butterworth ]

2. Filter Type

Select the kind of filter between low-pass, high-pass, band-pass, band-stop.

  • Type identifier : Filter type (0xfa20178e, 0x4cba62e9)
  • Default value : [ Band Pass ]

3. Filter Order

Order $ n $ of the filter, with $ n \geq 1 $.

  • Type identifier : Integer (0x007deef9, 0x2f3e95c6)
  • Default value : [ 4 ]

4. Low Cut-off Frequency (Hz)

Low cut-off frequency $ f_1 > 0 $ for high-pass, band-pass and band-stop filters (not used with low-pass filter). Low cut-off frequency can not be above Nyquist-Shannon criteria (half of the sampling rate).

  • Type identifier : Float (0x512a166f, 0x5c3ef83f)
  • Default value : [ 1 ]

5. High Cut-off Frequency (Hz)

High cut-off frequency $ f_2 > 0 $ for low-pass, band-pass and band-stop filters (not used with high-pass filter). For band-pass and band-stop filters, $ f_1 < f_2 $. High cut-off frequency can not be above Nyquist-Shannon criteria (half of the sampling rate).

  • Type identifier : Float (0x512a166f, 0x5c3ef83f)
  • Default value : [ 40 ]

6. Band Pass Ripple (dB)

If Chebychev filter is selected, pass band ripple in dB is a necessary information.

  • Type identifier : Float (0x512a166f, 0x5c3ef83f)
  • Default value : [ 0.5 ]

Examples

Let's consider our input signal is very noisy (50 Hz). To filter this signal, select a Low pass Butterworth filter of 4th order and High Edge equal to 30 Hz for example.

Miscellaneous