Changes between Version 2 and Version 3 of Processing/LidarNoisyPoints


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Timestamp:
Feb 22, 2012 9:39:10 AM (8 years ago)
Author:
mark1
Comment:

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  • Processing/LidarNoisyPoints

    v2 v3  
    1515When a point has been identified as being 'noise' it is given a classification value of '7'. All other points will probably have classification of '0' (unclassified) or '1' (default). The classification values used follow the ASPRS standard LiDAR point classes.
    1616
    17 It is advised that these points be removed before using the data, unless they are of specific use to your studies. ARSF-DAN included a utility for removing these points from the ASCII files called 'pt_cloud_filter'. To remove them from LAS files it is suggested to download the LASTools package, specifically the las2las tool.
     17It is advised that these points be removed before using the data, unless they are of specific use to your studies.  
    1818
    1919=== Removing noisy points from ASCII files ===
    2020
     21ARSF-DAN include a utility for removing these points from the ASCII files called 'pt_cloud_filter', which has both linux and Windows versions.
     22
     23To use, open the command line interface (in Windows: click start → click run → type ‘cmd’). Then type:
     24
     25{{{
     26pt_cloud_filter [input_ascii_file] [classification number(s) to be removed] > [output_filename]
     27}}}
     28
     29For example:
     30{{{
     31pt_cloud_filter.exe point_cloud.txt 7 > filtered_point_cloud.txt
     32}}}
     33
     34will create a file called filtered_point_cloud.txt from the points in point_cloud.txt excluding those with classification 7.
     35
    2136
    2237=== Removing noisy points from LAS files ===
     38
     39To remove them from LAS files it is suggested to download the LASTools package, specifically the las2las tool.