Messages

1

General / Re: Underwater Photogrammetry with GoPro Hero 12

« on: September 04, 2024, 02:00:41 PM »

Guys I can not describe how I am grateful for your answers. Thanks a lot!

I don't have any chance of taking images from same port unfortunately...

I will try to dive to a pool to test your suggestions. Timelapse Mode, Calibration settings etc.

When I have a chance to get another go pro I will definitely try to collect data with two GoPros.

Thanks again I will let you guys know.

2

General / Re: Underwater Photogrammetry with GoPro Hero 12

« on: August 27, 2024, 12:27:40 AM »

What GoPro settings are you using?
And how are you scanning the site?

I use 2x GoPro 7s mounted on a 3m water pipe (making it 2x faster to scan the site)...  Add more cameras for more faster!
The GoPros are pointing down at the reef, or 'normal' to the slope.  I'm swimming maintaining a 4-5m distance to the reef/slope.  And swimming at cruising speed, non-stop.
They're set on 2 second timelapse photos, in Wide.  This give extra overlap going forward, as GoPros can't do 3 second timelapse intervals, sadly.

My scans come out amazingly flat, with only the very long scans showing a banana. Curving upwards.

Are you processing the images before adding them?  They need to be untouched.

I gather the trick to solving banana scans is to do a pass or two with the camera oblique, set at say 20 degrees, instead of 90 degrees/normal to the reef/slope... Also some diagonal passes can work apparently.

And are the GoPros in original GoPro dive housings?
Grabbing frames from a video shot with one of its SuperView settings would probably give terrible results.   Stick with timelapse photos in 'Wide'.

Thanks a lot for your kind answers.

1- I was capturing a video with wide settings and Hypersmooth "on". I made a research and it came out that when Hypersmooth is "on" It plays with the pixels and it is bad for photogrammetry.

2- I am scanning the site while I am swimming with same speed but just one angle. Maybe if I record the same site with two different angles it would give better results.

3- Thanks! But in that time I can not afford second camera probably. I will get it as soon as I can afford!

4- I am not pre-processing the photos.

5- Yes I am using original housing.

I will try the things you mentioned asap.

Also do you have any calibration while using the Agisoft Metashape? Like focal length and pixel size?

Thanks,
Best regards

3

General / Underwater Photogrammetry with GoPro Hero 12

« on: August 22, 2024, 03:08:03 AM »

Hi everyone,

I hope everyone's week going great.

I am new in the photogrammetry so I have a few questions.

I am trying to create a model of a construction above and below water.

There isn't anything wrong with the above-water side. The program works great.

But when I tried to create a model under water the structure I modeled looks crooked, while in reality it should be straight.

Here is the model: https://drive.google.com/file/d/1XhS7Z-Yz_a2_Z3EUtG7nJfGuvvcCX88p/view?usp=sharing

Should I use some filter or I have to modify the camera setting? I am using GoPro Hero 12 as I mentioned on the caption.

Any information will be great for me.

Thanks!