Agisoft versus WebODM

 

I lately compared Agisoft, a commercial desktop image processing software product with OpenDroneMap.

As said OpenDroneMap (OSDM) is free open-source software and Agisoft is commercial proprietary software.  I tested the software on difficult (forest) images, taken in northern Finland, in the late afternoon, during July 2020. The results were striking, Agisoft did not have any problems with the data, creating a decent orthomosaic and 3D model. I did not do much tweaking, and basically used the default settings.

WebODM and ODM however did have problems, I used the latest versions of the software, but the end result did show consistently a stripe of unmatched images in the SE part of the mosaic. It seemed that most parameters did not have any influence upon the result, only two had major effect, the min_max_features, which I set to 32000 and the image resolution, which I kept to the original size (-1).  The images were taken in two runs, about ten minutes apart to change batteries.

Based on these experiences I could say that it makes sense to take images using good conditions, fair wind, short exposure time and a lot of overlap. ODM is doing well under optimal conditions, but for less-than-optimal conditions Agisoft is the winner.

Agisoft mosaic

WebODM mosaic

WebODM demo

WebODM really impressive.

We trid WebODM, running the server on a cloud Ubuntu veritual machine. The test mterial consisted of 119 images, taken from a height of 75 maters. The WebODM interface worked flawless, 3D view is really impressive, with many options, like fly trough, measurement of height, length, area and volume. You can drape the textured model on top of the 3D model, which gives even more realistic views. Here are some screenshots of the test material ater processing. The processing took about two hours. Of course faster virtual machines can be build using more RAM and more processors. Also the command line OpenDroneMAp non-GUI software probably runs faster with large amounts of data.

Part of the orthomosaic, lots of detail, the orthomosaic can be used for example to plan forest management, landscaping etc.

DEM of the area, showing details like ditches, trees and buildings.

3D measurement of height, quite reliable.

3D rotation, helicopter flight, smooth and gives realistic views with texture drape.

Clip showing 2D and 3D, rotation and measurement tool.

Video clip showing rotation of textured model.

OpenDroneMap, Free Drone Mapping Software

If you have a drone, like a DJI Phantom, you possibly would like to make sometimes photo mosaics, or more precise orthoimages. Commercial software, however, is expensive and many users won’t spend thousands on software they will use only several times a year. There are various free mission planning software packages, like Pix4D, DJI Ground Station (DJI GS) which run on IOS, or Android tablets. Flyig a grid mission, collecting images and getting the data into your computer, you will need software to stich the images together. Here comes OpenDroneMap, a free, open source software package, running on Windows, Mac and Linux. For details go to https://www.opendronemap.org/ . I have run the software on a laptop computer, using the docker environment. There are now several options to use ODM, Nativel (Linux Ubuntu 16.04), through docker (Windows, Mac and Linux) or by using the WebODM API.

Easiest is possibly the WebODM, which gives you a browser GUI to overcome the problem of (not complicated actually) line commands. I have tested the software systematically, and in a desktop environment several hundreds of images can be converted into an orthophoto, digital elevation model (DEM) and point cloud. For larger datasets, I would use a cloud computing service, with for example 120 M RAM and 20 cores, I used this to process 2800 images successfully. For a desktop application I would suggest 32 M RAM as minimum, although 16 could work.

Nokia 8, battery

Nokia 8 – battery life, much better than other phones

After about one year with my Nokia 8, I can now tell that the battery life exceeded all my expectancies. In general, with normal use of network, WIFI and telephone communications, the recharge cycle has been better than two days, mostly three days, occasionally longer. The processor is fast, updating applications or Android system doe take very little time. Starting or restarting is also very fast.  The fingerprint screen unlocking is flawless and saves you a lot of time when opening the screen. The cameras (three) with a Zeiss lens are bright and produce clear images, even in less than optimal light conditions. In my opinion a great smart phone.

Nokia 8, first experiences

I changed my Nokia Lumia 1020 ”camera” phone for a new Nokia 8 Android. The Windows system has de facto come to an end, and I used the phone only for its superb camera, which I used on y field trips. However, it was time to change, and the new Nokia 8 just looked right.

The Nokia 8 has great satellite navigation capabilities, GPS, GLONASS, BEIDOU, Galileo and QZSS, all present systems can be used. I had to test several GPS applications before I got the right one, showing all, e.g. GPS test by barbeauDev LINK. The only problem with the Galileo GNSS seems to be that the system is not yet complete yet. I live in northern Finland and I see only occasionally one to five satellites. However, satellite fix and position accuracy seems to be much better than with my Sony Xperia, elevation is much more accurate and stable, but due to present winter temperatures, I have not made any real accuracy tests outside.  But, inside, and even in an airplane the navigation works flawless.

Other things I like are the clean Android, no “added” software reducing battery time, clear screen, fingerprint screen lock, even a barometer, which you can use to check elevation or changes in weather. Camera has the old renowned Zeiss optics, 13 MP, and autofocus works with no problems (unlike my Sony). It has also a fron and back camera which can be used simultaneously to take selfy and landscape (although I do not know if I would use it). The price is really good, around 400 €, with 64 GB memory, and real quality design that is good value.

Microsoft Onedrive Files On Demand

Microsoft did it at last, finally we got back the off-line file system. Onedrive is a great thing, but the constant downloading and uploading of files to all your devices became a big nuisance. The other problem is the fact that tablets usually have limited space on flash disks, and this meant you could not use Onedrive at all. Now this has changes with the newest Widows 10 version. Onedrive Files On Demand works fine, but has to be explicitly activated. This is a relatively simple procedure, and is explained on

 https://support.office.com/en-us/article/learn-about-onedrive-files-on-demand-0e6860d3-d9f3-4971-b321-7092438fb38e

You can now choose to use files locally (Off-Line use) of directly from the cloud, saving space and syncing time. The system works very well, and I have experienced no problems at all, even at low network speed.

Galileo, where is it?

Galileo the European satellite navigation system became operational 15th December 2016, so now it has been working for nearly a year. Galileo will be more precise than the American GPS or Russian GLONASS systems. But when combined the time to get a fix on your position will be reduced and the accuracy improved, especially in buildup or forested areas.

However, said this, where are the Galileo enabled devices? My Sony Xperia shows me GPS, GLONASS and the Chinese BeiDou, but no Galileo. A quick look on the USEGALILEO.EU site will give you an overview of the availability of enabled mobile phones or other devices, like drones. At date there are 29 mobile phones listed which are Galileo enabled, for example Nokia 8, iPhone 8, Samsung S8, Sony Xperia XZ Premium, mostly high-end phones. Only 19 drones are listed, usually expensive professional use devices

So if you aim to  get extra accuracy to your positioning, drone or smart phone, I advise to check the technical information of the products you are interested in.