Skip to main content
  • EN

We are doing surveys of areas using drones. Images are taken directly from above with a very large overlap, which is required to create 3D models and point clouds. This works perfectly in software like Pix4D and DroneDeploy. As an alternative, we are trying to use FME to mosaic the images together, but cannot even get two images to be properly stitched together. As this should be a very simple task, I assume we are missing something very basic. I have tried to go through other tutorials/posted questions regarding this issue, but could not find anything that helped.

 

The test workflow reads two JPG images (there are actually thousands of images, but we are testing with two adjacent images) and sends this to the Raster Mosaicker. The only way that I got the two images to be mosaicked was to set the "Overlapping Values" to Average or Sum, but the end result is an image that looks a bit like a water mark (colour faded) with certain parts of the two images duplicated at the wrong spots.

 

I have also tried to use the RasterBlendMosaicker, but no luck with this either.

 

Is there perhaps any obvious thing that I am missing here? Attached is the workflow and the two test images. Any help is highly appreciated.

 

 

There is no georeferencing on the JPG files. FME does not know where the images are located geographically, and will just mosaic them on top of each other. The images must have a geotransform and projection before you can run them through FME and get the result you want.

There is no georeferencing on the JPG files. FME does not know where the images are located geographically, and will just mosaic them on top of each other. The images must have a geotransform and projection before you can run them through FME and get the result you want.

Hi Mbu

 

Thank you for the advice. I realised now that Pix4D and DroneDeploy reads the EXIF data of the JPG files in order to georeference it, wheareas this needs to be done as an additional step in FME. I managed to georeference the photos with the PhotoCoordinateExtractor transformer and then sending that to the Raster Georeferencer. I still need to find a way however to rotate all the photos so that the mosaicking is done properly. Currently the images are offset some distance over each other, but it does not create a coherent image. I was hoping this will be handled by the Raster Georeferencer automatically. From what I gather from another post (https://community.safe.com/s/question/0D54Q000080hEFhSAM/use-exif-information-in-jpeg-for-georeferencing-in-order-to-create-a-mosaic), it seems what I am trying to achieve might not be so easy to do with FME.

 

Thanks in any case for the advice - My main question was answered.

Is there any solution found about this issue since that last update?

Is there any solution found about this issue since that last update?

Unfortunately not. It seems Pix4D and DroneDeploy are better at handling this.

Reply


Community Stats

30,163
Posts
114,502
Replies
37,815
Members
Terms & ConditionsCookie settings
A product of
Safe Software respectfully acknowledges that we live, learn and work on the traditional and unceded territories of the Kwantlen, Katzie, and Semiahmoo First Nations.