Point Cloud Lat. & Long.

[Anonymous]

Is there any way to get the Lat. & Long. from a point cloud that an Las File has been used to create a surface, so that I can line up the Bing image correctly. I have no defined object in the surface file only contours and of course the cloud points.

When I originally download all the different files I was hoping to find a shape/breakline file of sorts that would show the existing building, roads ...ect.

I think the info may be in a file that has an *.IMG extension and properties says that it is a "Disk Image File". How do I get this file to work?

2015 In Use

Dave Z.

[Pointdump · Accepted solution]

Dave Z,

The only way to know for sure is to get the metadata from the site you lifted the Point Cloud from. It will be there somewhere.

I dunno what an img file is.

Dave S

[Pointdump]

Dave Z,

Is this where you're getting your data?

Always dig up the Metadata.

Dave S

[Anonymous]

Yep that's it. I will check after I eat

[Pointdump]

Dave Z,

Another really important thing that the metadata tells you is the classifications of the Point Cloud, whether it contains all classifications or just Bare Earth:

• 
  0 – Created, Never Classified
  1 – Unclassified
  2 – Ground
  3 – Low Vegetation
  4 – Medium Vegetation
  5 – High Vegetation
  6 – Buildings
  7 –Low Point (Noise)
  8 – Model Key-Point
  9 – Water
  10 – Reserved
  11 – Reserved
  12 – Overlap

This will give you a quick visual of different classifications:
https://rapidlasso.com/lastools/lasground/

Dave S

[Anonymous]

Is the metafile something I need to download and attach

[Pointdump]

Dave Z,

Yes, definitely keep it close to your data. (I keep it in the same folder as I store the point cloud.) The Metadata (data about data) is the only way you'll know for sure what Coordinate System and Vertical Datum you've got. It will also tell you if you've got Bare Earth (Ground Classification) points or whether you'll first have to filter out everything but ground.

Dave S

[Pointdump]

Dave Z,

I just downloaded a 95MB "Bare Earth" file from the Kansas DASC site, and I got a file named "BE_14SNH2050.img". I haven't a clue how to use it. I've never before seen a ".img" file. I'll nose around the Innertubes a bit.

Dave S

[Pointdump]

Dave Z,

I was able to crack it open with QGIS and even generate a shapefile of contours. How to bring an ".img" into C3D, I dunno. An even bigger mystery is why, oh why, would Kansas choose that strange file format.

Dave S

[Pointdump]

Dave Z,

Looks like C3D users have been scratching their heads since 2012 trying to figure out how to get that weirdly formatted Kansas data into AutoCAD:
http://forums.autodesk.com/t5/autocad-civil-3d-general/large-img-lidar-file/td-p/3481188

Dave S

[Anonymous]

May have to find an alternate site for the next time

[Pointdump]

Dave Z,

I haven't looked at any of their other data. The "Bare Earth" data seems to only come in the ".img" file format. Try the "Raw" or other files.

I'm going to check out Microdem tomorrow morning.

Dave S

[Hidden_Brain]

the IMG format is being used by USGS national map as well these days. I have access to arcmap (you do not need spatial or 3d analyst for this, just plain arcmap), which makes the conversion easy. just add the IMG to arcmap, and export as binary grid (adf) format that can be used in C3D.

Without arcmap, I do not have much idea how to process IMG. Thanks to you now I know that QGIS is also an option.

[AllenJessup]

---

@Pointdump wrote:

How to bring an ".img" into C3D, I dunno.

---

I use FW Tools or OpenEV_FW to convert the .img file to a GeoTiff. Maybe QGIS will do that?

[Pointdump]

Hi Allen,

QGIS definitely will. I tried it yesterday.

I also tried Microdem, but couldn't figure out how it works. There's ZERO documentation anywhere.

I'll go check out FW Tools and OpenEV_FW. Sure would be nice if Autodesk would apply just a little effort to being able to use different file formats with their software. I'm glad that Global Mapper, QGIS, myriad freewares, and ESRI are happy to pick up the slack.

Dave

[AllenJessup]

Hello Dave,

OpenEV is a sub-tool of FWTools. It's good for converting one file at a time. FWTools has a command window (similar to DOS) where you can do multiple files.

Allen

[Pointdump]

Thanks Allen. Heading there now.

Dave

[Pointdump]

Allen,

"FWTools has a command window (similar to DOS)..."

I don't see any buttons to click. What do you do to make something happen?

Dave

[AllenJessup]

WARNING! Rabbit Hole ahead!!!

No buttons. No GUI. I'd suggest starting with OpenEV to get familiar with it. The routine you would use is gdal_translate. The format is as follows: The usage format would be gdal_translate <source file [alpha.img]> <destination file [alph.tif]>. Multiple source and destination files could be used. For a large amount of files I would write a batch file that would call the file names.

C:\Program Files (x86)\FWTools2.4.7>gdal_translate
Usage: gdal_translate [--help-general]
       [-ot {Byte/Int16/UInt16/UInt32/Int32/Float32/Float64/
             CInt16/CInt32/CFloat32/CFloat64}] [-strict]
       [-of format] [-b band] [-expand {gray|rgb|rgba}]
       [-outsize xsize[%] ysize[%]]
       [-unscale] [-scale [src_min src_max [dst_min dst_max]]]
       [-srcwin xoff yoff xsize ysize] [-projwin ulx uly lrx lry]
       [-a_srs srs_def] [-a_ullr ulx uly lrx lry] [-a_nodata value]
       [-gcp pixel line easting northing [elevation]]*
       [-mo "META-TAG=VALUE"]* [-q] [-sds]
       [-co "NAME=VALUE"]*
       src_dataset dst_dataset

GDAL 1.7.0b2, FWTools 2.4.7, released 2010/01/19

The following format drivers are configured and support output:
  VRT: Virtual Raster
  GTiff: GeoTIFF
  NITF: National Imagery Transmission Format
  HFA: Erdas Imagine Images (.img)
  ELAS: ELAS
  AAIGrid: Arc/Info ASCII Grid
  DTED: DTED Elevation Raster
  PNG: Portable Network Graphics
  JPEG: JPEG JFIF
  MEM: In Memory Raster
  GIF: Graphics Interchange Format (.gif)
  XPM: X11 PixMap Format
  BMP: MS Windows Device Independent Bitmap
  PCIDSK: PCIDSK Database File
  PCRaster: PCRaster Raster File
  ILWIS: ILWIS Raster Map
  SGI: SGI Image File Format 1.0
  SRTMHGT: SRTMHGT File Format
  Leveller: Leveller heightfield
  Terragen: Terragen heightfield
  GMT: GMT NetCDF Grid Format
  netCDF: Network Common Data Format
  HDF4Image: HDF4 Dataset
  ERS: ERMapper .ers Labelled
  ECW: ERMapper Compressed Wavelets
  JP2ECW: ERMapper JPEG2000
  FIT: FIT Image
  RMF: Raster Matrix Format
  RST: Idrisi Raster A.1
  INGR: Intergraph Raster
  GSAG: Golden Software ASCII Grid (.grd)
  GSBG: Golden Software Binary Grid (.grd)
  R: R Object Data Store
  PNM: Portable Pixmap Format (netpbm)
  ENVI: ENVI .hdr Labelled
  EHdr: ESRI .hdr Labelled
  PAux: PCI .aux Labelled
  MFF: Vexcel MFF Raster
  MFF2: Vexcel MFF2 (HKV) Raster
  BT: VTP .bt (Binary Terrain) 1.3 Format
  IDA: Image Data and Analysis
  USGSDEM: USGS Optional ASCII DEM (and CDED)
  ADRG: ARC Digitized Raster Graphics
  BLX: Magellan topo (.blx)
  Rasterlite: Rasterlite
  SAGA: SAGA GIS Binary Grid (.sdat)

[Pointdump]

Allen,

"WARNING! Rabbit Hole ahead!!!"

Uh....that's not a rabbit hole. That's a CHASM as wide as the Grand Canyon.

Just. Shoot. Me. Now.

Let's assume for a second that I'm smart enough to understand DOS Programming. (May the dogs gnaw Bill Gates bones in Hades for all eternity) How do I "start with OpenEV"?

Dave