Forum

Author Topic: Depth Filtering Mode for UAV Imagery (lots of trees)  (Read 7563 times)

Fernandoker

  • Newbie
  • *
  • Posts: 21
    • View Profile
Depth Filtering Mode for UAV Imagery (lots of trees)
« on: July 05, 2014, 06:17:01 AM »
Ok, I have lots of trees (40% of the area) in my 800 pics uav dataset, is it better to use mild, moderated or agressive filtering in dense cloud? At agisoft manual it reads:

Quote
If the geometry of the scene to be reconstructed is complex with numerous small details on the
foreground, then it is recommended to set Mild depth filtering mode, for important features not
to be sorted out.
If the area to be reconstructed does not contain meaningful small details, then it is reasonable to
chose Aggressive depth filtering mode to sort out most of the outliers.General workflow
12
Moderate depth filtering mode brings results that are in between the Mild and Aggressive
approaches. You can experiment with the setting in case you have doubts which mode to choose.
« Last Edit: July 05, 2014, 06:23:17 AM by Fernandoker »

AndyC

  • Newbie
  • *
  • Posts: 30
    • View Profile
Re: Depth Filtering Mode for UAV Imagery (lots of trees)
« Reply #1 on: October 09, 2014, 01:16:47 AM »
Hi Fernandoker,

The best setting for this parameter will depend on what you want to use the resulting point cloud for?
For example, deriving a digital surface model (DSM) or a digital terrain model (DTM).

You'll need to be more specific about what you're trying to achieve,

Good luck,
Andy


mrb

  • Newbie
  • *
  • Posts: 47
    • View Profile
Re: Depth Filtering Mode for UAV Imagery (lots of trees)
« Reply #2 on: October 09, 2014, 10:40:21 PM »
Ok, I have lots of trees (40% of the area) in my 800 pics uav dataset, is it better to use mild, moderated or agressive filtering in dense cloud? At agisoft manual it reads:

Quote
If the geometry of the scene to be reconstructed is complex with numerous small details on the
foreground, then it is recommended to set Mild depth filtering mode, for important features not
to be sorted out.
If the area to be reconstructed does not contain meaningful small details, then it is reasonable to
chose Aggressive depth filtering mode to sort out most of the outliers.General workflow
12
Moderate depth filtering mode brings results that are in between the Mild and Aggressive
approaches. You can experiment with the setting in case you have doubts which mode to choose.

I notice almost no difference for most of my models when I change the depth filtering setting.  I usually just leave it on moderate.

andyroo

  • Sr. Member
  • ****
  • Posts: 405
    • View Profile
Re: Depth Filtering Mode for UAV Imagery (lots of trees)
« Reply #3 on: October 10, 2014, 03:17:57 AM »
I found the filtering behavior varied quite a bit not only with mild/moderate/aggressive, but also med/hi/ultra quality settings. For me the best way to evaluate ended up being to select a small (~50) image subset and generate a surface with each combination to compare.

Again, depends on your goal, for me I was looking for a good first-return surface (not filtering out trees but capturing canopy) since in dense forest I got basically zero ground points. I found that high/aggressive was the best solution for my needs.