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Messages - Walter Volkmann

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Yes, I also would like to see snapping functionality for vectorization. Otherwise you end up with gaps and overlaps in your vector coverage. You should be able to snap to lines or vertices of features for which you have already created shapes.

General / Re: Work Flow for GCP
« on: January 23, 2018, 02:13:48 AM »
Hi Geomaticist,

If you don't have PPK on board yet, no need to buy a new drone. Consider the V-Map system which is completely platform independent and weighs only 120g (about 4oz). If your drone can handle the extra 120g and has a space for the dual frequency antenna, you should be able to mount it on your existing drone. The only requirement is that the camera has an external flash hot shoe connector that delivers a pulse at mid-exposure. The V-Map system comes with free post-processing software that takes you through the whole work flow from RINEX conversion to trajectory computation to event position calculations to geo-tagging. You can use your existing survey grade GNSS receiver, a VRS, a network service or a second V-Map receiver as reference station.Have a look at There's a white paper there as well. Feel free to leave an enquiry. We will respond with technical info and pricing.

General / Re: Fusion of precision geotagged images with other images
« on: January 23, 2018, 01:20:01 AM »
Hi David,

We are doing the same as you are, only that we are using an RGB (GoPro) camera for the non-geotagged images. We have had no problems in getting both the geo-tagged Sony a6000 and the GoPro cameras aligned in the same alignment batch and judging by the sub-pixel alignment accuracy of the GoPro images, don't seem to suffer any degradation in overall accuracy. We still have to evaluate the resulting point cloud by means of validation points.

However, if in a separate alignment we use only the GoPro images (now geotagged with the positions as estimated in the first alignment), we strangely get large discrepancies between alignment output and geotagged camera positions. This does not make sense to me at all.  Until we have an explanation for this unexpected discrepancy we will have to always include the geotagged imagery (as baggage) in the approach. Nevertheless, the process does seem to give us the ability to align secondary (non event marking) cameras in combination with V-Map geo-tagged images - thus obviating the need for ground control.

We'll keep on working towards a more efficient solution.


« on: January 27, 2015, 03:15:23 AM »
Does anyone here have experience in using precise camera positions (coordinates from dual frequency kinematic GNSS) instead of Ground Control Points? What procedures/settings work best? Is it even worth it to use precise camera coordinates as primary spatial reference in SfM? Any discussion on this topic much appreciated.

General / Re: parametrezing texture atlas freez at 70%
« on: January 30, 2014, 07:32:07 PM »
I have a rather large dense point cloud and made a mesh with the latest version. When generating texture I get the 70% freeze again! Any ideas of how to overcome or what the limits in number of points/faces are?

General / Re: parametrezing texture atlas freez at 70%
« on: January 09, 2014, 07:52:50 PM »
Where can one download this version? Currently you can only get the 1795 version from And how can I get hold of an older version?

General / Re: Direct Georeferencing
« on: December 30, 2013, 02:55:34 AM »
I don't have a direct solution for you, sorry, but I recommend that you read up on kml. It is relatively easy to embed the UAV telemetry with links to your photos for some dramatic perspectives in Google Earth. It is particularly impressive with oblique shots.

Bug Reports / Re: Generating Mesh - 10% Stuck
« on: February 07, 2013, 04:59:24 PM »
Hi Ralf,

Thanks for the hint. Will it export a dense point cloud without having first completed the "Build Geometry" step in the workflow?

Bug Reports / Re: Generating Mesh - 10% Stuck
« on: February 06, 2013, 07:17:28 PM »
Thanks Alexey!

Bug Reports / Re: Generating Mesh - 10% Stuck
« on: February 06, 2013, 06:07:46 PM »
Hi Alexey,

Thanks for the quick response.

I have 24GB of RAM.

I use Arbitrary for Object Type, High for Target Quality, Smooth for Geometry Type, 0, 0 and 5 for the remaining parameters.

I should add that I am using a combination of vertical and oblique photographs in this project.

Best regards,


Bug Reports / Re: Generating Mesh - 10% Stuck
« on: February 06, 2013, 05:22:33 PM »
I have exactly the same problem. Funny thing is that while available memory is being used to near 100% levels, CPU runs at nearly zero capacity. I have recently installed a GEFORCE GTX 660 Ti card.   And not being able to to interrupt the mesh generating process forces me to end the program from Task Manager and thus I don't get the opportunity to save the log file. Any help to overcome this problem would be greatly appreciated.

Bug Reports / Can't export orthophoto
« on: October 31, 2012, 11:47:47 AM »
After more than six hours of exporting an ortho photo in geo-tiff I get the message "Can't export orthophoto. There is a tiff file of some 2.1GB on my disk but I can't open it because it is alledgedly damaged. I have attached the console text.

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