[Liblas-devel] Broken links and wrong dates
hobu.inc at gmail.com
Fri Mar 4 22:47:46 EST 2011
On Mar 4, 2011, at 7:03 PM, Ben Discoe wrote:
> Greetings all,
> I'm checking out libLAS and just joined the list. We (myself, at my
> day job) have been defining our own simple/fast point cloud format, so
> i'm checking out libLAS to either avoid reinventing the wheel (if LAS
> will suffice) or potentially to add support for our format to libLAS
> (if it doesn't :-)
LAS is a simple format, but it has a number of deficiencies depending on the scenario you plan to use it for. The original intent of the format was data interchange for hardware sensors, and it has accidentally become the GeoTIFF/Shapefile of LiDAR because of that.
I would say it's not a particularly good format for driving GUI applications (it is sequentially organized with no inherent spatial organization) and the fact that the fields are fixed ends up being a limitation for people wanting to do various things. It's also quite "fat" because of its fixed field nature, and does compress well with things like LASzip (http://laszip.org).
Michael Gerlek and I are currently in the middle of bootstrapping something tentatively called libPC, which is where you'd want to add your own point cloud-ish format support to. libLAS is expected to focus only on LAS moving forward (a libLAS 2.0 in some ways, if you will), and some of the various warts that libLAS has acquired for formats and operations will be moved over there as libPC is built up. Right now there's only a mailing list and a master repository.
libPC is expected to be focused more on data interchange, processing, and transformation (GDAL'ish) than visualization or real-time. If you want something on that end of the spectrum, I'd look at PCL (Point Cloud Library -- we sure suck at naming things) http://www.ros.org/wiki/pcl I hope that when libPC grows up, it can optionally fit into PCL as a data provider.
I will also note that we expect to have a strong showing for libLAS and libPC at the OSGeo Montreal Code Sprint in a couple of weeks, which will hopefully continue the momentum that Michael has been pushing lately.
> Just some points about the website/documentation that i found right off:
> 1. On http://liblas.org/download.html, it says:
> Current Release(s)
> * 2010-02-01
> Past Releases
> * 2010-1-7
> I'm quite certain that these are actually 2011, not 2010.
> 2. In Getting Started (http://liblas.org/start.html) and also on the
> download page (http://liblas.org/download.html) there is a link to
> sample data:
> or http://liblas.org/samples/
> These links are broken (404).
These are broken right now because something has been constantly pulling the sample library down and causing me to overrun my bandwidth allotment for liblas.org. I don't know what a good solution might be. I'm leaning toward having a landing page that has a login/password that people can use. This will hopefully allow humans to manually download stuff without the bots going bananas and sucking up all the bandwidth. I'll try to fix this up this week.
This file can be gotten from the hg repository because it is quite small.. http://hg.liblas.org/main/raw-file/5cd75fb456fa/test/data/srs.las
More information about the Liblas-devel