photogrammetry - Drone aerial imagery to QGIS

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.

Answer

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.