withheld bit ignored

[bayesmap]

Hi
It looks like the withheld bit is ignored when reading a LAS file.
The decompose option is checked and the log window displays "withheld flag values are the same(0)"
lasinfo reports " +-> flagged as withheld: 145" so the bits are set.
using version 2.10.2 on mac OS
Any ideas?
Andre

[daniel]

Can you share the file with us? (admin [at] cloudcompare.org)

[bayesmap]

Here is a scanline.
I set the synthetic, keypoint and withheld to 1 for negative scan angle, 0 otherwise.
Corresponding LAS classification 20 and 0.
They show up on lasinfo but all 3 are ignored in CloudCompare (classification works fine).

histogram of classification of points:
1382 never classified (0)
1410 Reserved for ASPRS Definition (20)
+-> flagged as synthetic: 1410
+-> flagged as keypoints: 1410
+-> flagged as withheld: 1410

[daniel]

Thanks for the data.

I was able to fix the bug and even improve the LAS I/O filter a little bit (it now handles the Offset flag for instance if you have point formats >= 6).

You can download the latest 2.11.alpha version (online).

Thanks for the feedback!

[bayesmap]

Hi,
I just tried the latest build on mac (2.11.1) and it still ignores the withheld flag.
The same version on linux works fine on the same file. So I guess the LAS I/O is somewhat different on mac?
Thanks,
André

[daniel]

Yes, and it's probably not the right version? Or have you compiled it yourself?

[bayesmap]

I used the latest version available for mac (2.11.1) downloaded from asmaloney.com

I can see this in the release notes for 2.11.2
LAS 1.3 or 1.4 (LASlib): Classification values and flags were not always loaded or saved properly
so I guess the mac version is too old and this fix is not available...