prototype software for validating LAS available for testing

[Martin Isenburg]

Hello,

to anyone who has followed what's been happening in these two
discussion groups it will probably not come as a surprise to hear that
rapidlasso GmbH has submitted a bid to the ASPRS call for proposals
for implementing the LAS Validation Suite (LVS). The fundamental
premise of our bid is to implement the LAS validation tool through an
open process that invites early feedback.

Providing an "official correctness check" for LAS files and especially
that of the Coordinate Reference System is likely to spark emotional
discussions. We doubt that any one party will - on their own and
behind closed doors - be able to develop a comprehensive LAS
validation software that will find acceptance by an already "slightly
suspicious" LiDAR community. We believe an open approach will disarm
any notions that such a software could be used as a "lock-out"
mechanism, will make the validation tool quickly available for
professional use, and will find result in a acceptance by the LiDAR
community.

To make our bid as strong as possible we have completed a partial
prototype of the LAS Validation Suite. With this we do not only want
to demonstrate our technical capability but also illustrates the way
we plan to inject transparency into the development process. The tool
is using the open source LASlibrary API which was designed
particularly for this bid. The LASlibrary package is an unrestricted
open source (LGPL 2.1) API to read LAS (optionally also LAZ) files. It
is a completely re-engineered subset of the LASlib API of LAStools
that has been drastically simplified to better suit the
being-light-weight-requirement of the ASPRS' request for proposals.

You can find this prototype tool, example input and output, our bid,
the call for proposals, and a few other goodies here:

http://github.com/LASvalidator

I invite you to run the 'lasvalidate.exe' prototype tool on your own
data, report bugs and other findings, suggest improvements to the XML
output, and else ...

prototype validation tool:
https://github.com/LASvalidator/lasvalidate/tree/master/bin

example data:
https://github.com/LASvalidator/lasvalidate/tree/master/data

collection unit tests (in progress):
https://github.com/LASvalidator/lasvalidate/tree/master/unit

No CRS handling is implemented yet. This is likely to be the most
tricky part. Using the "gold standard" by combining GeoTIFF with GDAL
and proj4 seems the way to go but may require some code juggling if we
want to minimize the amount of code dependencies on other packages.

Regards,

Martin @rapidlasso

PS: Please only post replies in "The LAS room" user forum since this
is not about LAStools but about the LAS format.

[Martin Isenburg]

Hello,

a few folks have reported problems in accessing the lasvalidate.exe
prototype tool though the somewhat non-intuitive github pages. Simply
go here:

https://github.com/LASvalidator/lasvalidate/blob/master/bin/lasvalidate.exe

and click "view raw" to download. Please let me know how you like/
dislike/agree/disagree/... with the current validation results on your
own data.

Regards,

Martin @rapidlasso

[Martin Isenburg]

Hello folks,

a few of you have inquired over the past weeks whatever happened to my
bid for the ASPRS LAS Validation Suite. It's been ... aehhhm ...
funny. I received a serious and professional looking letter marked
"business confidential" that said that I was selected to do the work
... but only on the precondition that I sign a document that more or
less said that I would only be able to talk about the development via
an official ASPRS channel. Why was that funny? Well, if you read my
bid then you know that at its very core was the intention to do the
entire development in an open and transparent manner that would invite
early and frequent community feedback. So it is still a mystery to me
why my bid was selected in the first place. Zähneknirschend (fig.
German) I decided to sign the "silencer" ... I was worried that the
alternative might be worse. The next funny thing was that the ASPRS
LAS committee members did not seem informed about all this. Instead a
"secret" technical review panel was deciding things. But the funniest
thing was that a couple of weeks after me signing the dreaded
"silencer" I was told that the ASPRS was canning whole project.
Shortly thereafter the ASPRS Executive Director announced his
retirement and I personally like to think - just because it makes it
even funnier - that this was somehow related to the LAS Validation
Suite contract fiasko ... (-;

Okay. Enough funny. Now serious. I have sunk many hours into this
project and would like to complete its development in open souce. The
main thing that is lacking for completion is the CRSscan library for
the GeoTIFF versus OCG WKT validation. I was thinking just calling the
right functions of GTIFF and GDAL could do this. I looked through
Frank Wanderdam's code and it seems fairly straight forward. To keep
the tool nice and small - like the original ASPRS LVS tender was
calling for - it would be nice to "rip" only those parts out of GTIFF
and GDAL that are needed to read the Geokey projection tags and the
OCG WKT string. We would then initialize a projection once from the
Geokey tags and once from the OGC WKT string and make sure they are
the same. For the time being I'd be happy if we support 98% (?!?) of
all cases by focusing on the most common projections such as UTM,
generic TM, generic LCC, generic OM, stateplanes, and latlong.

I just updated the github repository with all the necessary source
code to compile the current version of lasvalidate.exe (the LINUX
Makefile are untested and may still have a few errors).

http://github.com/LASvalidator

Regards,

Martin @rapidlasso

PS: Would be great to have some agency / company / institute funding the effort.

--
http://rapidlasso.com - fast tools for all you LiDARs