M2P 360° Panorama artifacts

[dawaske]

Hello everyone!
A few months ago I bought´a DJI Mavic 2 Pro and, after coming home from my first vacation with it, I noticed the following issue with some of the 360° Panoramas I shot using DJI Go 4:

For some reason, sometimes there are those darker areas in the lower half of the panorama. I used Autopano Giga v4.4.2 and an XML-file to stitch the 26 pictures together (the original files can be found HERE).

Have any of you encountered the same issue and (ideally) know how to fix it?

Cheers,
Daniel

 

[ff22]

Hello everyone!
A few months ago I bought´a DJI Mavic 2 Pro and, after coming home from my first vacation with it, I noticed the following issue with some of the 360° Panoramas I shot using DJI Go 4:

For some reason, sometimes there are those darker areas in the lower half of the panorama. I used Autopano Giga v4.4.2 and an XML-file to stitch the 26 pictures together (the original files can be found HERE).

Have any of you encountered the same issue and (ideally) know how to fix it?

Cheers,
Daniel

Hopefully, an expert will pop in. But I wonder if the sun caused that lower image to change exposure dramatically?

 

[dawaske]

I don't think it's the sun since the same happened on another panorama with cloudy skies.

 

[Paul2660]

Cool shot.

Are the darker areas in the actual images? Or being created by the pano software. If the latter try Microsoft ICE. Only will run on windows however.

Did you shoot both raw and jpg and if so are the darker areas on both files?

Paul C

 

[gnirtS]

Looks like a big exposure shift. Are you manual or auto exposure?

 

[dawaske]

Exposure was set to manual (Aperture 5.0, Shutter 1/80s, ISO 100). However, I just noticed that, even though those settings were supposed to be invariant, according to the EXIF data the aperture was different for some photos (up to three steps!). How is this possible!?

 

[Paul2660]

Strange, I would assume that may be the issue. I did a quick check on the few 180 degree, 360 degree and many 9 shot panos I have taken. All are in M mode and the camera setting remained static throughout (all have same settings). Might consider a camera reset from DJIGO4.

Paul C

 

[globetrotterdrone]

@gnirtS is on the right way, these are "artifacts" after the blending of wide exposure values of the inidividual image tiles.
As you took this image on sun rise/sun set you have the sun as the brightest and some deep shadows as the darkest areas. You easily face EV differences +/- 2 to 3.

The built-in blending (and stitching) mode you receive with the JPG is less than optimal and cannot handle these well.
I certainly always recommend you enable the individual shots of the panorama to be saved as DNG and do all the work in post on PC.
You have far more headroom then.

 

[dawaske]

Sorry for the late reply! @globetrotterdrone Does that mean those artifacts are due to the stitching software (Autopano) and not the drone?

 

[globetrotterdrone]

No, the other way around.
Stitching of 20 MP images (26 with the M2P for a rough 330° panorama) needs a considerable amount of horse power to do it properly. Find overlapping images, stitch and blend them together. Although this is done in the drone and the respective JPG is available as output, these are rather fast iterations.

The composite image you attached, shows problems with the dynamic range. The sun is very bright but the shadows of the mountains are already relatively dark. Between these bright and dark areas, the software tries to blend. The in-built algorithm works well but at such extremes, you then see very dark pieces of the sole images within the composite.

If you hand over the DNG to a separate programm like Photoshop, Autopano etc. which can handle RAW files and offer settings within the process, I am pretty sure you get better stitched and blended final composites. The automatic stitch by the M2P cannot be altered at any time and sometimes produces results as what you have shown.

 

[dawaske]

The thing is, the panorama in my first post actually was created using Autopano and the 26 individual JPGs (I just had to scale down the resolution of the panorama to reduce the file size). Currently I'm not saving the DNGs to keep storage consumption down.

 

[globetrotterdrone]

Too bad, compared to DNG JPG has less headroom for those exposure spreading ...

 

[Thomas B]

The thing is, the panorama in my first post actually was created using Autopano and the 26 individual JPGs (I just had to scale down the resolution of the panorama to reduce the file size). Currently I'm not saving the DNGs to keep storage consumption down.

I use 64GB SD cards in my drones. I save images as jpeg+DNG. You’l be Able to fly 8-10 batteries and never get the card full.
As a precaution against image loss, I do change my card every flight in most circumstances.