Public Lab Research note


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Mobius NDVI

by FrankA |

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https://youtu.be/XiKFT191cUg

Please visit the above website.

NDVI Phantom 2 with Mobius camera Blue filter - post processed using "FIJ"I software.InfraBlueNDVI. Lut.

I wrote a macro for FIJI to post process the images... from the Mobius into : Tiff or Jpg into the type of Lut that best represented the data information I was after. Each run was producing 200+ images..

The processing time was 1minute 25 seconds. I then loaded the sequence into iMovie and played around with the timelapse. Using the FIJI LUTs was easy... TRY it YOURSELF.

BTW any camera with the IR filter removed / changed will give the same results.

You need the FIJI app. the Macro I wrote allows you to select - on the fly, your own input AND output folder: l have set "type" to jpeg - this works well with Imovie.

Mobius files are prefixed with IMA.. we use this to collect all the original "blue" files. I used an IMAC for this ...

You may need to source the InfraBlueNVDI. lut files (Plus other luts online).. Mine was done ages ago

NDVIBlu2RedWB.lut NDVIBlu2Red.lut NDVI_VGYRM.lut infraBlueNDVI.lut NDVI_VGYRM (1).lut

name the Macro... NDVI.txt...... MACRO TEXT BELOW: just copy and paste into a text file and save it.

adir = getDirectory("");
setBatchMode(true); run("Image Sequence...", "open=[adir] file=IMA sort use"); mydir = getDirectory(""); run("Split Channels"); run("infraBlueNDVI"); run("Calibration Bar...", "location=[Upper Right] fill=None label=Black number=5 decimal=0 font=12 zoom=2 overlay"); run("Image Sequence... ", "format=JPEG save=[mydir]")

run("Close All");

setBatchMode(false);

Once you have your original "BLUE" files: OPen the Plugins tab: Macros... Run. Then select the macro: select the input folder and files and run.

You should end up with converted files in the Results folder

drop me a line if issues: frank.aldous@btinternet.com



ndvi infrared health plant infra-red mobius-actioncam mobius mobius-action-cam


3 Comments

https://youtu.be/Vff--FWRfTo

addendum how to file : sorry about the Clip quality.... NEW clip to follow in due course. I realised the Caiibration Bar was not appearing on the final image outputs.. (although shown on the images in the stack)


Dear FrankA, Greetings from Nepal, I have a mobius actioncam ( Green Blue and Near Infrared ) which is modified to take near infrared spectrum for plant health analysis NDVI...i have attached it (facing vertically downward as shown in attached image) to a drone (DJI Phantom 3 Professional) for aerial mapping and plant health analysis. I took multiple images in time lapse of every 1 second...but the images are very much distorted (due to vibration, fish eye effect, some other distortions ) is there any ways to correct those distortions caused due to fast moving drone? My plan is to use Agisoft Photoscan to stich those multiple images and create an orthomosaic and run NDVI algorithm for plant health analysis.....but i am stuck with these distortions.i saw the photo of your drone, i wanted to ask did you add anything for controlling vibration effect of drone on the camera? I am impressed with your results. suggest me what should i do to get better image acquisition for NDVI calculation.

Thanks in advance Regards, Suman

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Hi Suman.

This is my setup… Mobius Action cam Docking station + Foam anti vibration tubing… all held on with quick release cable ties. I have the 6mm lens from Public labs

I set the unit in parallel to the main camera on the front right leg (- with a slight forward bias to counter the tilt of the quadcopter when flying forward). This gives me the opportunity to use both cameras in tandem.

I also use Clip - on prop guards and mount a 10gram weight on the opposite rear guard at the furthest point and underneath the plastic guard. - This balance weight is essential to get the Quadcopter to be in balance. (I use two 5gm car wheel stick-on balance weights.)

I set my airspeed to 13 miles per hour and the time lapse at 5seconds.. this gives me plenty of overlap and the quad is flying level at all times.

( As I now know what the camera is seeing I have removed the Transmitter unit from the mount and also the battery that was supplying power for the transmitter (mounted on the opposite rear leg)

Mobius ActionCam FPV Docking Station with Mini Video Transmitter 5.8GHz 32ch 200mW = $38.23 - From Hobbyking

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and these foam mounts

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Occasionally I get some slight distortion from vibration (jello) - this is very noticeable in video mode. Other than that

I use Fiji App and embed LUTS from NDVI sources. to get my batch system running I wrote a Macro : This processes all my images. Currently typical run is 400+ photos. this takes about 1min 30 secs to process I then send everything to iMovie and create timeline video.. or just send the finished images to an iCloud folder for later use.

Hope this helps


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