I have a bigger project of ca 22 000 images (1.9 TB) which I am trying to process into one orthomosaic and digital surface model (DSM). I split up the project into 12 subsets using Pix4D with ca 2000 images in each subset. Then my workflow was:
- Do initial processing with all subsets
- Merge projects:
- Add Manual Tie Points (MTP) in Project A
- Add the same MTP in Project B (name them the same)
- Reoptimize in each project
- Create new project with the option “Project Merged from Existing Projects”
- Choose to treat objects with the same name as he same
- Click finish
- Further Processes
I tried to merge 5 of the subsets and run all steps and when I started to inspect the dense point cloud I realized there are some problems. Sometimes at the border between the subsets there is a misalignment and a gap in the pointcloud:
Here we can see an area between to subsets:
If we zoom in we can see that the images were taken under different light conditions:
And here the misalignment becomes visible:
Here is another example at the road:
I guess this misalignment will cause artefacts in the DSM and since my goal is to to DSM analysis I would like the DSM to have as high accuracy as possible.
Any ideas what can be the problem here and how can I solve it?
Are the images taken in sun too different from the ones taken under cloudy conditions?
Would it help to add more MTP in the errorous areas?
Should I better perform all steps on each subset and then merge them in another program?
Btw I cannot provide a quality report because Pix4D crashes every time I try.
Thanks in advance