las2txt doesn't recognize the -precision or -header parameters

[Nicholas Pilkington]

I'm converting a .las file to .csv and trying to keep 4 decimal places of precision and a header:

wine bin/las2txt -i points.las -parse xyzRGB -o out.csv 

work, but with either of the following it complains:

wine bin/las2txt -i points.las -parse xyzRGB -precision 4 4 4 -o out.csv

wine bin/las2txt -i points.las -parse xyzRGB -header pound -o out.csv

I found the precision parameter here:

https://www.liblas.org/utilities/las2txt.html

Nick

[Martin Isenburg]

Hello Nick,

You found a page of the old libLAS tools that are a November 2007 fork off from LAStools and that unfortunately use the same names for a few tool but renamed some of the parameter names.

wine bin/las2txt -i points.las ^

                             -parse xyzRGB ^

                             -set_scale 0.001 0.001 0.001 ^

                             -o out.csv

See the accompanying README file for the possible commands:

http://lastools.org/download/las2txt_README.txt

Hope these are just small LAS files ... (-:

Martin @rapidlasso

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[Nicholas Pilkington]

Unfortunately this does not work. This command works:

wine bin/las2txt -i points.las -parse xyzRGB -o out.csv

But this fails:

wine bin/las2txt -i points.las -parse xyzRGB -set_scale 0.001 0.001 0.001 -o out.csv

with:

ERROR: cannot understand argument '-set_scale'

I have read the readme and there is not mention of that parameter. There is a rescale parameter but not definition of what it does for las2txt?

[Martin Isenburg]

Hello,

Sorry. I was not thinking straight. The waves were big today and I swallowed too much salt water. What I told you only works for txt2las because there it makes sense. The resolution (e.g. the decimal digits) of the coordinates in a LAS file are determined in the LAS header and increasing the resolution (e.g. going from cm = 0.01 to mm = 0.001 scale factors) will not make the coordinates more precise but simply add a trailing zero without significance.

If you want to do that (for some odd reason) then it is indeed the '-rescale' command that can add what I call "coordinate fluff" (aka fake resolution).

wine bin/las2txt -i points.las -parse xyzRGB -rescale 0.001 0.001 0.001 -o out.csv

Regards,

Martin @rapidlasso