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Running the tracker on a blipmovie saved with an exclusion zone is broken

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    2013 April 10:  Users have reported problems with running the tracker on a blipmovie which was recorded with an enabled exclusion zone.

    The problem appears due to the fact that the excluded blips are still written to the blipmovie file, but with zeroed data and class "excluded".  This is probably not what should happen, but needs more thought.

    Fix:

    For now, to process such files, you can enable the R filtering expression "max > 0" in the blip processing window, as shown in the yellow-highlighted region of this image:

    filter_zeroed_blips.png

    This serves to filter out those zombie blips which are being zeroed by the exclusion zone, but not removed from subsequent processing.

    To do this in a batchparm.R file, make sure that the blip = list portion includes these highlighted lines:

    blip = list (
    
            ... 
            
            ## should a blip filtering expression be used?
    
            use.blip.filter.expr = TRUE,
    
            ## what is the blip filtering expression?
    
            blip.filter.expr = max > 0
    
            ),
    

    If you were already using a filtering expression XXXX, then change it to (XXXX) & max > 0.  For example:

    perim < 2.5 * area  
    

    becomes

    (perim < 2.5 * area) & max > 0
    
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     filter_zeroed_blips.png
    how to enable filtering of zeroed excluded blips
    32.1 kB13:53, 10 Apr 2013JohnActions
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