**************************************************************** lasnoise: This tool flags or removes noise points in LAS/LAZ/BIN/ASCII files. The tool looks for isolated points according to certain criteria that can be modified via '-step 3' and '-isolated 3' as needed. The default for step is 4 and for isolated is 5. It is possible to specify the xy and the z size of the 27 cells separately with '-step_xy 2' and '-step_z 0.3' which would create cells of size 2 by 2 by 0.3 units. The tool tries to find points that have only few other points in their surrounding 3 by 3 by 3 grid of cells with the cell the respective point falls into being in the center. The size of each of the 27 cells is set with the '-step 5' parameter. The maximal number of few other points in the 3 by 3 by 3 grid still designating a point as isolated is set with '-isolated 6'. By default the noise points are given the classification code 7 (low or high noise). Using the '-remove_noise' flag will instead remove them from the output file. Alternatively with the '-classify_as 31' switch a different classification code can be selected. Another option is the '-flag_as_withheld' switch which sets the withheld flag on the points identified as noise. It is also important to tell the tool whether the horizontal and vertical units are meters (which is assumed by default) or '-feet' or '-elevation_feet'. Should the LAS file contain proper projection VLRs then there is no need to specify this explicitly. Internally the step size in xy or in z direction will be multiplied with 3 if the coordinates are found or are specified to be in feet. The size of the grid cells needs to be changed with '-step 0.0001' or similar if the input is in geographic longlat representation. You can avoid having certain points being classified, marked withheld, or removed with the '-ignore_class 2' option. Please license from martin@rapidlasso.com before using lasnoise commercially. Please note that the unlicensed version will set intensity, gps_time, user data, and point source ID to zero, slightly change the LAS point order, and randomly add a tiny bit of white noise to the points coordinates once a certain number of points in the input file is exceeded. For updates check the website or join the LAStools mailing list. http://rapidlasso.com/ http://lastools.org/ http://groups.google.com/group/lastools/ http://twitter.com/lastools/ http://facebook.com/lastools/ http://linkedin.com/groups?gid=4408378 Martin @rapidlasso **************************************************************** example usage: >> lasnoise -i tiles\*.laz ^ -step 2 -isolated 3 ^ -odix _denoised -olaz ^ -cores 7 classifies all points that have only 3 or fewer other points in their surrounding 3 by 3 by 3 grid (with the respective point in the center cell) where each cell is 2 by 2 by 2 meters in size as classification code 7. >> lasnoise -i lidar.las ^ -remove_noise ^ -ignore_class 2 ^ -o lidar_without_noise.laz removes all points - except those classified as 2 (ground) - that have only 5 or fewer other points in their surrounding 3 by 3 by 3 grid (with the respective point in the center cell) where each cell is 4 by 4 by 4 meters in size. >> lasnoise -i tiles_raw\*.laz ^ -classify_as 31 ^ -step_xy 1 -step_z 0.2 -isolated 5 ^ -odir tiles_denoised\ -olaz ^ -cores 3 running on whole folder of files on 3 cores where each cell being only 1 by 1 by 0.2 meters in size and where points that have only five or fewer other points in the 27 cell neighborhood of their surrounding 3 by 3 by 3 grid are considered noise. here points are classified to class 31 instead of being removed. **************************************************************** overview of all tool-specific switches: -v : more info reported in console -vv : even more info reported in console -quiet : nothing reported in console -version : reports this tool's version number -fail : fail if license expired or invalid -gui : start with files loaded into GUI -cores 4 : process multiple inputs on 4 cores in parallel -ignore_class 1 3 4 5 6 7 9 : ignores points with specified classification codes -ignore_extended_class 42 43 45 67 : ignores points with specified extended classification codes -ignore_single : ignores single returns -ignore_first : ignores first returns -ignore_last : ignores last returns -ignore_first_of_many : ignores first returns (but only those of multi-returns) -ignore_intermediate : ignores intermediate returns -ignore_last_of_many : ignores last returns (but only those of multi-returns) -ignore_withheld : ignores points flagged withheld -ignore_overlap : ignores points flagged overlap (new LAS 1.4 point types only) -by_flightline : processes points of each flightline separately (needs populated point source IDs) -step 1.0 : use 1 x 1 x 1 uniform grid for finding isolated points -step_xy 2.0 : set the horizontal x and y spacing of the grid to 2 -step_z 0.5 : set the vertical z spacing of the grid to 0.5 -isolated 20 : points are isolated when there is a total of less than 20 points in all neighhour cells -classify_as 7 : set classification code of isolated points to 7 -flag_as_withheld : mark isolated points by turning their withheld flag to on -remove_noise : remove noise points from the file -mem 2000 : set amount of in-core memory to use for isolation grid to 2000 MB -remain_buffered : write buffer points to output when using '-buffered 25' on-the-fly buffering -dont_remove_empty_files : do not remove files that have zero points remaining from disk -ilay : apply all LASlayers found in corresponding *.lay file on read -ilay 3 : apply first three LASlayers found in corresponding *.lay file on read -ilaydir E:\my_layers : look for corresponding *.lay file in directory E:\my_layers -olay : write or append classification changes to a LASlayers *.lay file -olaydir E:\my_layers : write the output *.lay file in directory E:\my_layers **************************************************************** for more info: E:\LAStools\bin>lasnoise -h Filter points based on their coordinates. -keep_tile 631000 4834000 1000 (ll_x ll_y size) -keep_circle 630250.00 4834750.00 100 (x y radius) -keep_xy 630000 4834000 631000 4836000 (min_x min_y max_x max_y) -drop_xy 630000 4834000 631000 4836000 (min_x min_y max_x max_y) -keep_x 631500.50 631501.00 (min_x max_x) -drop_x 631500.50 631501.00 (min_x max_x) -drop_x_below 630000.50 (min_x) -drop_x_above 630500.50 (max_x) -keep_y 4834500.25 4834550.25 (min_y max_y) -drop_y 4834500.25 4834550.25 (min_y max_y) -drop_y_below 4834500.25 (min_y) -drop_y_above 4836000.75 (max_y) -keep_z 11.125 130.725 (min_z max_z) -drop_z 11.125 130.725 (min_z max_z) -drop_z_below 11.125 (min_z) -drop_z_above 130.725 (max_z) -keep_xyz 620000 4830000 100 621000 4831000 200 (min_x min_y min_z max_x max_y max_z) -drop_xyz 620000 4830000 100 621000 4831000 200 (min_x min_y min_z max_x max_y max_z) Filter points based on their return numbering. -keep_first -first_only -drop_first -keep_last -last_only -drop_last -keep_second_last -drop_second_last -keep_first_of_many -keep_last_of_many -drop_first_of_many -drop_last_of_many -keep_middle -drop_middle -keep_return 1 2 3 -drop_return 3 4 -keep_single -drop_single -keep_double -drop_double -keep_triple -drop_triple -keep_quadruple -drop_quadruple -keep_number_of_returns 5 -drop_number_of_returns 0 Filter points based on the scanline flags. -drop_scan_direction 0 -keep_scan_direction_change -keep_edge_of_flight_line Filter points based on their intensity. -keep_intensity 20 380 -drop_intensity_below 20 -drop_intensity_above 380 -drop_intensity_between 4000 5000 Filter points based on classifications or flags. -keep_class 1 3 7 -drop_class 4 2 -keep_extended_class 43 -drop_extended_class 129 135 -drop_synthetic -keep_synthetic -drop_keypoint -keep_keypoint -drop_withheld -keep_withheld -drop_overlap -keep_overlap Filter points based on their user data. -keep_user_data 1 -drop_user_data 255 -keep_user_data_below 50 -keep_user_data_above 150 -keep_user_data_between 10 20 -drop_user_data_below 1 -drop_user_data_above 100 -drop_user_data_between 10 40 Filter points based on their point source ID. -keep_point_source 3 -keep_point_source_between 2 6 -drop_point_source 27 -drop_point_source_below 6 -drop_point_source_above 15 -drop_point_source_between 17 21 Filter points based on their scan angle. -keep_scan_angle -15 15 -drop_abs_scan_angle_above 15 -drop_abs_scan_angle_below 1 -drop_scan_angle_below -15 -drop_scan_angle_above 15 -drop_scan_angle_between -25 -23 Filter points based on their gps time. -keep_gps_time 11.125 130.725 -drop_gps_time_below 11.125 -drop_gps_time_above 130.725 -drop_gps_time_between 22.0 48.0 Filter points based on their RGB/CIR/NIR channels. -keep_RGB_red 1 1 -keep_RGB_green 30 100 -keep_RGB_blue 0 0 -keep_RGB_nir 64 127 -keep_NDVI 0.2 0.7 -keep_NDVI_from_CIR -0.1 0.5 -keep_NDVI_intensity_is_NIR 0.4 0.8 -keep_NDVI_green_is_NIR -0.2 0.2 Filter points based on their wavepacket. -keep_wavepacket 0 -drop_wavepacket 3 Filter points based on extra attributes. -keep_attribute_above 0 5.0 -drop_attribute_below 1 1.5 Filter points with simple thinning. -keep_every_nth 2 -drop_every_nth 3 -keep_random_fraction 0.1 -keep_random_fraction 0.1 4711 -thin_with_grid 1.0 -thin_pulses_with_time 0.0001 -thin_points_with_time 0.000001 Boolean combination of filters. -filter_and Transform coordinates. -translate_x -2.5 -scale_z 0.3048 -rotate_xy 15.0 620000 4100000 (angle + origin) -translate_xyz 0.5 0.5 0 -translate_then_scale_y -0.5 1.001 -switch_x_y -switch_x_z -switch_y_z -clamp_z_below 70.5 -clamp_z 70.5 72.5 -copy_attribute_into_z 0 -copy_intensity_into_z Transform raw xyz integers. -translate_raw_z 20 -translate_raw_xyz 1 1 0 -translate_raw_xy_at_random 2 2 -clamp_raw_z 500 800 Transform intensity. -set_intensity 0 -scale_intensity 2.5 -translate_intensity 50 -translate_then_scale_intensity 0.5 3.1 -clamp_intensity 0 255 -clamp_intensity_above 255 -copy_RGB_into_intensity -copy_NIR_into_intensity Transform scan_angle. -scale_scan_angle 1.944445 -translate_scan_angle -5 -translate_then_scale_scan_angle -0.5 2.1 Change the return number or return count of points. -repair_zero_returns -set_return_number 1 -set_extended_return_number 10 -change_return_number_from_to 2 1 -set_number_of_returns 2 -set_number_of_returns 15 -change_number_of_returns_from_to 0 2 Modify the classification. -set_classification 2 -set_extended_classification 0 -change_classification_from_to 2 4 -classify_z_below_as -5.0 7 -classify_z_above_as 70.0 7 -classify_z_between_as 2.0 5.0 4 -classify_intensity_above_as 200 9 -classify_intensity_below_as 30 11 -classify_intensity_between_as 500 900 15 -change_extended_classification_from_to 6 46 -move_ancient_to_extended_classification Change the flags. -set_withheld_flag 0 -set_synthetic_flag 1 -set_keypoint_flag 0 -set_overlap_flag 1 Modify the extended scanner channel. -set_scanner_channel 2 -copy_user_data_into_scanner_channel Modify the user data. -set_user_data 0 -scale_user_data 1.5 -change_user_data_from_to 23 26 -change_user_data_from_to 23 26 -copy_attribute_into_user_data 1 Modify the point source ID. -set_point_source 500 -change_point_source_from_to 1023 1024 -copy_user_data_into_point_source -copy_scanner_channel_into_point_source -merge_scanner_channel_into_point_source -split_scanner_channel_from_point_source -bin_Z_into_point_source 200 -bin_abs_scan_angle_into_point_source 2 Transform gps_time. -set_gps_time 113556962.005715 -translate_gps_time 40.50 -adjusted_to_week -week_to_adjusted 1671 Transform RGB/NIR colors. -set_RGB 255 0 127 -set_RGB_of_class 9 0 0 255 -scale_RGB 2 4 2 -scale_RGB_down (by 256) -scale_RGB_up (by 256) -switch_R_G -switch_R_B -switch_B_G -copy_R_into_NIR -copy_R_into_intensity -copy_G_into_NIR -copy_G_into_intensity -copy_B_into_NIR -copy_B_into_intensity -copy_intensity_into_NIR Supported LAS Inputs -i lidar.las -i lidar.laz -i lidar1.las lidar2.las lidar3.las -merged -i *.las - merged -i flight0??.laz flight1??.laz -i terrasolid.bin -i esri.shp -i nasa.qi -i lidar.txt -iparse xyzti -iskip 2 (on-the-fly from ASCII) -i lidar.txt -iparse xyzi -itranslate_intensity 1024 -lof file_list.txt -stdin (pipe from stdin) -rescale 0.01 0.01 0.001 -rescale_xy 0.01 0.01 -rescale_z 0.01 -reoffset 600000 4000000 0 Fast AOI Queries for LAS/LAZ with spatial indexing LAX files -inside min_x min_y max_x max_y -inside_tile ll_x ll_y size -inside_circle center_x center_y radius Supported LAS Outputs -o lidar.las -o lidar.laz -o xyzta.txt -oparse xyzta (on-the-fly to ASCII) -o terrasolid.bin -o nasa.qi -odir C:\data\ground (specify output directory) -odix _classified (specify file name appendix) -ocut 2 (cut the last two characters from name) -olas -olaz -otxt -obin -oqfit (specify format) -stdout (pipe to stdout) -nil (pipe to NULL) LAStools (by martin@rapidlasso.com) version 171215 (non-profit) usage: lasnoise -i in.laz -o out.laz lasnoise -i raw\*.laz -step 2 -isolated 3 -odir D:\denoised -olaz lasnoise -i raw\*.laz -step_xy 1 -step_z 0.25 -isolated 10 -classify_as 7 -odix _denoised -olaz lasnoise -i *.laz -step 4 -isolated 5 -olaz -remove_noise lasnoise -i *.laz -step_xy 2 -step_z 0.5 -isolated 10 -flag_as_withheld -odix _denoised -olaz lasnoise -i tiles\*.laz -step 3 -isolated 3 -classify_as 31 -odir denoised -olaz lasnoise -h ------------- if you find bugs let me (martin@rapidlasso.com) know.