[pdal] Support for BAG file format

[Howard Butler]

I think what we should implement is a "GDAL" reader. The GDAL reader would take in any GDAL-readable raster, convert each band to a dimension, and assign an individual XY (and maybe Z) for each point based on the pixels in the raster. For typical single band imagery, this would result in just an XYZ point cloud (regularly spaced, of course). For multiband stuff, we could add an option that allows you to specify the dimension mapping.

This approach would allow us to leverage GDAL's BAG reader without having to entirely write our own driver. We could then make native drivers for GDAL-readable formats as we need to going forward.

Sound like a good idea?

Howard

> On Sep 3, 2015, at 10:43 AM, Dan Ames <dan.ames at byu.edu> wrote:
> 
> Thanks Howard. All I've got right now is a 700MB file which is too big to experiment with. I'll see if we can get a couple of small examples put together next week and post them. Looks like this is going to be a more common file in the future since these inexpensive velodyne LiDAR pucks are growing in popularity. Not sure why we can't get it to just generate LAS files but we'll do whatever we have to do I suppose! - Dan
> 
> On Thu, Sep 3, 2015 at 7:09 AM Howard Butler <howard at hobu.co> wrote:
> 
> > On Sep 2, 2015, at 11:04 AM, Dan Ames <dan.ames at byu.edu> wrote:
> >
> > Hi all,
> >
> > Glad to see that PDAL is still under very active development! (last commit 1 hour ago!)
> >
> > Quick question: We have a new Velodyne VLP 16 LiDAR Puck that generates data in a .BAG file format.
> >
> > Does PDAL support this file? We'd like to convert it to LAS...
> 
> PDAL does not support BAG at this time, but it is a very simple format. Do you have a few small example files we can permanently add to the test suite? Maybe we could whip something up...
> 
> Howard
>