data compression mechanism
data compression mechanism
Is there a way to compress the data files that ActiveView produces?
-
Coen
- Site Admin
- Posts: 1152
- Joined: Fri Mar 26, 2004 7:00 pm
- Location: Amsterdam, Netherlands
- Contact:
The data can be re-sampled to a lower sample rate with the Decimator tool from http://www.biosemi.com/download/BDF-to-decimatedBDF.zip . You will of course reduce the bandwidth of the data (new -3 dB point is at 0.2616 multiplied by the new sample rate), so use the tool wisely.
Compression tools like ZIP and RAR are not too effective on EEG data, because the recorded signal is very similar to 1/f noise (pink noise). A reduction of approx. 50% is usually the best that can be achieved.
Best regards, Coen (BioSemi)
Compression tools like ZIP and RAR are not too effective on EEG data, because the recorded signal is very similar to 1/f noise (pink noise). A reduction of approx. 50% is usually the best that can be achieved.
Best regards, Coen (BioSemi)
Last edited by Coen on Thu Aug 03, 2006 11:00 pm, edited 1 time in total.
Deciminator tool
When I tried to use the Decimator tool, it asked for a .vi, .ctl, .vit, or .ctt file. What are these files, and where would they be saved?
-
Coen
- Site Admin
- Posts: 1152
- Joined: Fri Mar 26, 2004 7:00 pm
- Location: Amsterdam, Netherlands
- Contact:
If you run BDF-todecimatedBDF.exe: make sure you have the LabVIEW run-time-engine version 7.1 properly installed (RTE is freeware, available from ftp://ftp.ni.com/support/labview/window ... imeEng.exe)
If you run BDF-todecimatedBDF.llb: make sure you have LabVIEW 7.1 or higher installed (not free, see www.ni.com)
Best regards, Coen (BioSemi)
If you run BDF-todecimatedBDF.llb: make sure you have LabVIEW 7.1 or higher installed (not free, see www.ni.com)
Best regards, Coen (BioSemi)