Georeferenced Image file

Hi Forum,

I have an georeferenced 2D Raster file (tif) that I would like to import into Rhino using the right coordinates. After exporting the Image from DroneDeploy, I end up with 3 files:

  1. the actual image (*.tif)
  2. a klm file
  3. a tfw file.

I guess that the klm and tfw file are there to specify the images size and location, so I opened them with notepad, this is what I got:

KLM:

?xml version=“1.0” encoding=“UTF-8”?
kml xmlns=“http://earth.google.com/kml/2.2
Document
GroundOverlay
Icon
href>3DFlightPlan_Orthomosaic_export_ThuJul16115208432172.tif</href
/Icon
LatLonBox
north>42.57926666666667</north
south>42.577986111111116</south
east>-83.26123888888888</east
west>-83.26295555555555</west
/LatLonBox
name>3DFlightPlan_Orthomosaic_export_ThuJul16115208432172.tif</name
drawOrder>1</drawOrder
/GroundOverlay
/Document
/kml

TFW:

        0.0099999998
        0.0000000000
        0.0000000000
       -0.0099999998
 -9268789.8747174796
  5248149.6364602651

I cannot really make sense out of this, does somebody have experiences with this kind of setup?

thank you !

Andreas

Hi Andreas -

" The positioning of a ground overlay is controlled by the tag. Bounding values are given for the north and south latitudes, and east and west longitudes. In addition, rotation values are given for images whose y -axis doesn’t coincide with grid north. This example uses a JPEG image for the overlay. Google Earth also supports BMP, GIF, TIFF, TGA, and PNG formats."

(https://developers.google.com/kml/documentation/kml_tut)

Does that help at all?

-Pascal

thanks Pascal,

I already suspected it to be something like this… however, the numbers appear to be quite weird…
Why don’t the just give us coordinates… that would be so much easier…

Andreas

Wrong spelling. These files are called KML (Keyhole Markup Language) files.

1 Like

Hi Andreas -
Just a few FWIW’s…

You did get the coordinates in the KML file: a box between 42.577986º south, 42.579266º north, 83.262955º west and 83.261238º east.

One degree doesn’t have the same distance in meters at all locations on the planet.

You don’t need the KML and TFW file - the TIFF file should be geotagged and contains the information. You can use a program like QGIS to extract the bounding box and size per pixel in longitude and latitude information.

Generally, you wouldn’t want to have the terrain appear far-from-origin in Rhino. In Rhino 7, there shouldn’t be issues with that but I believe that the recommendation is still to have geometry around the world origin.

I’m not aware of plug-ins that will bring in geoTIFF’s into Rhino in the real-world location. The Grasshopper Bison plug-in will bring it in at the Rhino origin. I can’t remember if there are options in the Grasshopper Gismo, Mosquito, … plug-ins. I’m not sure what LANDS design does - last time I checked, it didn’t like the formatting of the TIFF file that I tested - @albert would be able to tell you.
-wim

you are right, sorry …

Thank you very much Wim for all the valuable information !
I already tried QGIS yesterday and as you said I was able to import the tiff file and it seems to be the right scale. Now I am trying to export it, or the bounding box of it into a format which is accessible for rhino.

Just a bit background information :
The tiff originates from a drone survey, and was exported from DroneDeploy, I try to use it as a reference to validate some site plan information. Usually I would simple import it using the “picture” command and then rotate/scale it by using two reference point I can clearly identify on both the picture and the CAD data, If the points are relatively far away this is normally good enough.

However since in this case I try to get the best available absolute precision, I don’t want to modify the data if possible (e.g. by manually scaling it…), so it would be valuable to me to have the precise measurements of the picture, so I am able to scale it in rhino accordingly.

Hi Andreas -

Bison will create a 1:1 scaled terrain if you correctly enter the x and y pixel size. QGIS will report those sizes. The geometry will be brought in around the Rhino world origin but at the correct elevation.
-wim

I was able to measure the length of the bounding box dimensions in QGIS.
I than used this length and scaled the image I imported with the “picture” command in Rhino.
I believe I could also get the world coordinates from QGIS, and then move the scaled picture accordingly, but right now the rest of my data is not geo-referenced so I am fine for now.
thanks again for the help!