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I used Phantom DJI Standard 3 drone for some aerial photos of an archaeological site. When I viewed the properties of the jpeg file, it contained Longitude (like this: 22; 14; 37.701258239) and Latitude (like this: 41; 24; 33.58346), and also elevation attributes. However, when I try to add the image to QGIS, it's not in the geographical place that it should be.

Do I need to georeference the images even if they have Long/Lat values already, and why it doesn't work with the Lat/Long information available like this?

I'm using WGS 84.

  • 1
    Have a look at Open Drone Map – user2856 Jul 18 '16 at 21:06
  • Wht do you hope to produce with these images? – nickves Jul 18 '16 at 23:26
  • How far away from the actual site are the photos? Is it a matter of a few metres, hundreds of metres, or kilometeres? – Simbamangu Feb 12 '17 at 14:43
  • Can it present Nad 83? Need that in my block of the woods. – user93242 Mar 12 '17 at 4:13
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Yes you need to Georeference the images. The Exif data explains where the photo was taken, so it describes where your drone/camera was at that time and often many other values (heigth, bearing etc). QGIS and mapping packages work off a different method of locating the image and usually require a location of the center of the upper left pixel, knowledge of the pixel size in the x and y space, offset and rotation values.

The good news is there are quite few products out there do do the georeferencing and a number of them (if not all) offer fully functional trial periods.

We use a P3 and use PhotoScan by Agisoft to get georeferenced images into QGIS. Its expensive but has a generous trial period.

We also tried these product below and they also offer trials for you to see how it works:

  1. Pix4D which can get expensive but can be rented per month. (We didnt buy because it was too expensive for us)
  2. DroneDeploy was a hosted solution and reasonably priced I thought. (We didn't buy because we wanted to process locally)
  3. Maps Made Easy was also a hosted solution and reasonably priced. (We didn't buy because we wanted to process locally)

I have heard good things about Open Drone Map that @Luke mentioned in a comment but I have not personally used it.

I have also seen on forums that some people are using a free product called Microsoft Image Composite Editor to mosaic their images and then georefence them with GDAL with or QGIS. This forum discussion starts off with someone who mosaics 20,000 Hectares with Microsoft ICE and a guy further down shares how he georeference a Microsoft ICE image using GDAL_Translate.

  • 2
    I wouldn't go with the last paragraph. That wouldn't eliminate the camera distortion from the raw UAV images. – nickves Jul 18 '16 at 23:24
  • Cool - good to know! – Andrew Jeffrey Jul 18 '16 at 23:27
  • @AndrewJeffrey you did'nt mention the QGIS georeferencer. Why? – birdybird03 Jul 19 '16 at 15:24
  • @DzoleGJ I mentioned georeferencing in QGIS in the last paragraph, I didn't explicitly mention the tool but thats what I was referring to. Personally I would use the QGIS georeferencer to georeference an image that has already been mosaiced, I wouldn't use it to georeference 20-50 images that just came from my drone. If you are only wanting one or two images from your drone to be in QGIS then yes I would use the QGIS georeference as an excellent capable free tool. – Andrew Jeffrey Jul 19 '16 at 21:55
  • @nickves I wonder if Hugin image stitcher would work, because that one does eliminate a lot of camera distortion. I'll be taking some aerial photos next week and am going to give it a shot so we don't have to georeference every image, but a few stitched together ones instead. I can provide those results here (maybe just update my answer) when we're done. – SaultDon Jul 19 '16 at 23:14
4

Give RAPID for DJI a try. It will geo-reference and process up to 100 images from any DJI sensor or drone for free. The results are WGS84 Lat/Lon GeoTIFF format digital elevation models, point clouds and orthomosaic maps.

Disclaimer: I wrote the software and dronemapper.com SaaS service. Thanks!

2

You will probably have to georeference them!

The metadata you're describing is really useful to let you know where the photo was taken, and it's usually a good first step that helps you understand where the area is that the image needs to be georeferenced against.

See if your drone provides other information like image orientation (North, South, West, etc..)? That's usually helpful too. I've never used that drone before so can only inquire if it's available, sorry.

But the QGIS georeference plugin is describer here, and there is a tutorial outlining the steps needed to georeference an ortho photo in QGIS. Those should be more than enough to get you started, good luck.

  • 1
    I think the issue is more complex. Do you have a orthophoto or the individual images acquired by the drone? Usually the process of producing an orthorectified image from separate images is done by specialized software like Visual SFM (open source) Pix4d or Photoscan (paid license). Usually you have some ground control points in the image(s) that you can use to produce a geometrically corrected image (orthophoto). Is this the case? – Gerardo Jimenez Jul 18 '16 at 22:29
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Georeferencing single images taken from Drone, doesn't make much sense. EXIF data in single image means location of Drone and in case of Phantom with accuracy around +-5m of location. That's center of the image and that is not enough to get any usable results other than just locate image.

What other were referring was image processing with photogrammetry software to get results like point cloud, DSM, Orthophoto,... But in order to do that, images must minimum overlap 60 % (side way and along flight).

To the list of above sofware I would also add 3Dsurvey. It has some unique features, nice tutorials on web page and trial version. Check it out here: 3Dsurvey.si

0

Hi I've been through the whole research bit on this subject and settled with Open Drone Map when all my trials ended. It's flakey on a mac and wouldn't work on Safari so I run it through Chrome instead.

Andy

  • Your question needs clarification. I know about ODM and I suspect you refer about webODM. Desktop ODM works in Mac through a Vagrant or Debian virtual machine... It only works in linux environment – aldo_tapia Oct 30 '17 at 20:11
0

You can use the Georeferencer GDAL plugin that comes natively with QGis.

If you know where you took the photos it is quite simple to georeference images in a point-and-click manner using the georeferencer. A tutorial can be found here.

Make sure you use enough points to successfully georeference the image (too few can cause image warping).

0

You may check these matlab scripts that I created for georeferencing of UAV imagery. One script is for producing a world file associated with each image and the other script is for producing a KML file for viewing the images on Google Earth at their correct locations. Please note that accurate X,Y, altitude and heading data for each image are needed for best results.

  1. https://gist.github.com/EvangelosAlevizos/eb164b905f713a215b960e61b91b198b#file-uav2kml-m
  2. https://gist.github.com/EvangelosAlevizos/eb164b905f713a215b960e61b91b198b#file-uav2world-m
  3. https://gist.github.com/EvangelosAlevizos/eb164b905f713a215b960e61b91b198b#file-readme_uav2world_uav2kml_scripts-txt

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