Project work
The project work is done using Matlab. In the work, there are four different noisy signals originating from a (real!) industrial process. Your task is to filter each of the four signals - according to instructions below - with three different filters. In each case, two filters are given (see table 1), and the third one you may choose freely. Note that you should not use any filter twice in the work.
Filtering instructions for signals:
Signal | Filter 1 | Filter 2 | Filter 3 |
1 | (r,s)-fold Wisorized mean | FIR median hybrid | your choice |
2 | impulse detecting | average controlled local average | -''- |
3 | selective average | selective median | -''- |
4 | LUM smoother | Wilcoxon | -''- |
Write a brief report including your filter implementations (Matlab m-files), plots of filtered signals and your conclusions about the results. The report should be returned by January 31st 1998 to course assistant Esa Alhoniemi (room F415 in the Laboratory of information and computer science).
Some instructions
Matlab
Matlab is available (at least) in the workstations in Maarintalo. If you use it elsewhere, note that the basic Matlab package is sufficient for the work - no toolboxes are needed.
How to get the signals?
Go to the web page of the course http://www.cis.hut.fi/cis/edu/Tik-61.181/ The signals file signals.mat can be obtained via link Signals on the page. Save the signals into your home directory using your web browser. (In Netscape, for instance, this can be done so that move your mouse pointer on the Signals link, press right mouse button, and choose Save link as... option from the pop-up menu.)
The signals can be loaded to Matlab using command load signals. After this, you have four variables (700-point vectors) signal1...signal4 in your workspace, which you can verify using command whos.
Problems?
If you have something to ask about Matlab or the project work, please contact course assistant Esa Alhoniemi (email esa.alhoniemi@iki.fi).