|
tomwalters@0
|
1 .TH CONV 1 "1 September 1993"
|
|
tomwalters@0
|
2
|
|
tomwalters@0
|
3 .SH NAME
|
|
tomwalters@0
|
4 conv \- Convolution.
|
|
tomwalters@0
|
5
|
|
tomwalters@0
|
6 .SH SYNTAX
|
|
tomwalters@0
|
7 conv [options] signal_file impulse_response_file
|
|
tomwalters@0
|
8
|
|
tomwalters@0
|
9 .SH DESCRIPTION
|
|
tomwalters@0
|
10 The response of a linear filter to an arbitiary input signal is the
|
|
tomwalters@0
|
11 convolution of the signal with the filter's impulse response.
|
|
tomwalters@0
|
12 The `impulse_response_file' contains the impulse response which characterises the
|
|
tomwalters@0
|
13 filter, and the result of the convolution operation is the response of
|
|
tomwalters@0
|
14 that filter to the signal contained in the `signal_file'.
|
|
tomwalters@0
|
15
|
|
tomwalters@0
|
16 The `signal_file' must consist of binary 16-bit numbers (ie. shorts).
|
|
tomwalters@0
|
17 The `impulse_response_file' must consist of binary floats.
|
|
tomwalters@0
|
18 The output signal is the same length as the input signal and is written on
|
|
tomwalters@0
|
19 the stdout in binary 16-bit numbers.
|
|
tomwalters@0
|
20
|
|
tomwalters@0
|
21 If the `signal_file' consists of an impulse train, then the output should
|
|
tomwalters@0
|
22 be a repeated impulse response, ie. should be a repeated version of the
|
|
tomwalters@0
|
23 `response_file'.
|
|
tomwalters@0
|
24
|
|
tomwalters@0
|
25
|
|
tomwalters@0
|
26
|
|
tomwalters@0
|
27 .SH OPTIONS
|
|
tomwalters@0
|
28
|
|
tomwalters@0
|
29 1. length
|
|
tomwalters@0
|
30
|
|
tomwalters@0
|
31 The amount of the signal file to convolve in time units (s or ms) or in
|
|
tomwalters@0
|
32 samples (no units). Time units are converted to samples using the given
|
|
tomwalters@0
|
33 `samplerate' option. The string "max" is recognised as the remainder of
|
|
tomwalters@0
|
34 input.
|
|
tomwalters@0
|
35
|
|
tomwalters@0
|
36 2. domain
|
|
tomwalters@0
|
37
|
|
tomwalters@0
|
38 Select algorithm for convolution. In the time domain ("domain=time") the
|
|
tomwalters@0
|
39 discrete convolution formula is applied directly as a local averaging
|
|
tomwalters@0
|
40 operation on the input signal with weights obtained by time-reversing and
|
|
tomwalters@0
|
41 shifting the impulse response. The impulse response is assumed to be zero
|
|
tomwalters@0
|
42 for all time outside the given file. In the frequency domain
|
|
tomwalters@0
|
43 ("domain=frequency") the FFT of the whole input signal is multiplied by a
|
|
tomwalters@0
|
44 frequency response function (the FFT of the impulse response), and
|
|
tomwalters@0
|
45 the result inverse FFT'd.
|
|
tomwalters@0
|
46
|
|
tomwalters@0
|
47 3. scale
|
|
tomwalters@0
|
48
|
|
tomwalters@0
|
49 A scale factor for scaling the output.
|
|
tomwalters@0
|
50
|
|
tomwalters@0
|
51
|
|
tomwalters@0
|
52 .SH "SEE ALSO"
|
|
tomwalters@0
|
53 options smooth fft acf
|
|
tomwalters@0
|
54
|
|
tomwalters@0
|
55 .SH COPYRIGHT
|
|
tomwalters@0
|
56 .LP
|
|
tomwalters@0
|
57 Copyright (c) Applied Psychology Unit, Medical Research Council, 1995
|
|
tomwalters@0
|
58 .LP
|
|
tomwalters@0
|
59 Permission to use, copy, modify, and distribute this software without fee
|
|
tomwalters@0
|
60 is hereby granted for research purposes, provided that this copyright
|
|
tomwalters@0
|
61 notice appears in all copies and in all supporting documentation, and that
|
|
tomwalters@0
|
62 the software is not redistributed for any fee (except for a nominal
|
|
tomwalters@0
|
63 shipping charge). Anyone wanting to incorporate all or part of this
|
|
tomwalters@0
|
64 software in a commercial product must obtain a license from the Medical
|
|
tomwalters@0
|
65 Research Council.
|
|
tomwalters@0
|
66 .LP
|
|
tomwalters@0
|
67 The MRC makes no representations about the suitability of this
|
|
tomwalters@0
|
68 software for any purpose. It is provided "as is" without express or
|
|
tomwalters@0
|
69 implied warranty.
|
|
tomwalters@0
|
70 .LP
|
|
tomwalters@0
|
71 THE MRC DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
|
|
tomwalters@0
|
72 ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
|
|
tomwalters@0
|
73 THE A.P.U. BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES
|
|
tomwalters@0
|
74 OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
|
|
tomwalters@0
|
75 WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
|
|
tomwalters@0
|
76 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
|
|
tomwalters@0
|
77 SOFTWARE.
|
|
tomwalters@0
|
78
|
