Smartphone images

[nsicart]

Hello, good evening

I’m doing some test with smartphone images, not drone images. I want to scan a street and a playground. Im making this test with an iphone and an android device and the 3D results are very good.

But, I don’t get the results geolocated. The images taken have their GPS information though…

Do you know why and how to solve it?

Thanks

[nsicart]

[Gordon]

How much precision do the GPS coordinates have in the EXIF data?

My old Samsung S8 only records to the nearest arc second, ie about 30 metres, so it is essentially useless for most of the areas I’m likely to be imaging with the phone.

[nsicart]

I don’t know the accuracy but the results, for example the orthophoto should appear somewhere near to the place when I open it on Qgis… Shouldn’t it?

It appears on the middle of the world

Thanks

[Saijin_Naib]

Does it show a gray globe with a question mark next to it in the Layers list?

[Gordon]

Can you post an image somewhere publicly available so we can check the EXIF data?

[nsicart]

You can check the images and the results here

https://drive.google.com/drive/folders/1yjjOlHXMzuERpgGRBNu4zM4NhttKjVLi?usp=share_link

[Gordon]

The good news is that the altitude, longitude and latitude appear to be recorded with nanometre precision, although I’m pretty sure the last 12 digits are a bit dodgy

I’m downloading the images now and will see if the geolocation works for me.

[Gordon]

Geolocation is fine, but the ortho and 3D model are not very good for a couple of reasons.

Images of water surfaces are always pretty difficult due to lack of features- in this case the water is crystal clear, but refraction changes the relative positions of the rock paving on the bottom when photographed from different positions. This makes feature matching difficult.

Some of the images have strong reflections that hide the bottom of the pool, so it would be better to use a polarising filter.

Also, shading the lens to stop direct sunlight hitting the lens would stop those internal reflections, which are visible on a number of images.

[Tim]

@Gordon,
You beat me to it! and your stitch looks a lot better than the one I did (on ultra settings ), what settings did you use?

[Gordon]

With these images I doubt it is possible to get a decent ortho.

86 images 00:56:52

|Options:|auto-boundary: true, dem-resolution: 1, dsm: true, gps-accuracy: 2, mesh-octree-depth: 13, mesh-size: 600000, orthophoto-resolution: 1, pc-quality: ultra, pc-rectify: true, use-3dmesh: true|
|Average GSD:|0.06 cm|
|Area:|144.65 m²|
|Reconstructed Points:|11,735,645|

[nsicart]

Thanks,

I wasn’t looking for a good othophoto in this ocasion. It was just a test…

I have processed the images using webodm.net and my results were not georeferenced… but then I tried again and it was georeferenced… I don’t know why…

But well, thanks