[GRASS-dev] r.in.lidar tuning

[Markus Neteler]

(back to an older topic)

On Tue, Oct 8, 2013 at 8:37 PM, Markus Neteler wrote:
> On Tue, Oct 8, 2013 at 4:31 PM, Markus Metz  wrote:
>> Markus Neteler wrote:

[ wish for r.in.lidar: ]
...
>>>     filter   Only import points of selected return type
>>>               If not specified, all points are imported
>>>              options: first,last,mid
>>>
>>> which would be great for r.in.lidar as well to avoid that I need to
>>> split the file with las2las beforehand.
>>
>> Why would you want to do filtering? The r.in.lidar methods min, max,
>> mean, median, percentile are not sufficient?

For some LAS files not.

> I omitted to mention the sometimes existing classification of returns
> and had in mind to be able to restrict the import to e.g. ground
> points only, or the like. Then apply the methods min, max, etc only to
> the selected subset of LiDAR points.

I have implemented that now in
http://trac.osgeo.org/grass/changeset/60247/grass/trunk/raster/r.in.lidar

(hope I got it right over from v.in.lidar)

Concerning Doug's intensity wish which also became mine yesterday:
Attached a patch to import intensity values rather than z values (flag -i).
Using -i all statistics are applied to intensity.

The code is a bit simple ("ugly") since the variable names further on
in the code remain related to "z" rather than e.g. become a generic
"value". Not sure if all related variables should be renamed, hence I
didn't commit that to SVN.
Please try from svn + attached patch.

markusN
-------------- next part --------------
Index: raster/r.in.lidar/main.c
===================================================================
--- raster/r.in.lidar/main.c	(revision 60271)
+++ raster/r.in.lidar/main.c	(working copy)
@@ -146,7 +146,7 @@
     struct Option *input_opt, *output_opt, *percent_opt, *type_opt, *filter_opt;
     struct Option *method_opt, *zrange_opt, *zscale_opt;
     struct Option *trim_opt, *pth_opt, *res_opt;
-    struct Flag *print_flag, *scan_flag, *shell_style, *over_flag, *extents_flag;
+    struct Flag *print_flag, *scan_flag, *shell_style, *over_flag, *extents_flag, *intens_flag;
 
     /* LAS */
     LASReaderH LAS_reader;
@@ -277,6 +277,11 @@
     shell_style->description =
 	_("In scan mode, print using shell script style");
 
+    intens_flag = G_define_flag();
+    intens_flag->key = 'i';
+    intens_flag->description =
+        _("Import intensity values rather than z values");
+
     if (G_parser(argc, argv))
 	exit(EXIT_FAILURE);
 
@@ -761,7 +766,11 @@
 
 	    x = LASPoint_GetX(LAS_point);
 	    y = LASPoint_GetY(LAS_point);
-	    z = LASPoint_GetZ(LAS_point);
+	    if (intens_flag->answer)
+		/* use z variable here to allow for scaling of intensity below */
+		z = LASPoint_GetIntensity(LAS_point);
+	    else
+		z = LASPoint_GetZ(LAS_point);
 
 	if (return_filter != LAS_ALL) {
 	    int return_no = LASPoint_GetReturnNumber(LAS_point);