Messages

16

General / Re: GCP and marker problem

« on: March 03, 2023, 09:42:52 AM »

I think the accuracy is really how the position data gets weighted. So maybe your XMP values are too low. If you want your resulting orthomosaic to match the GCPs, you need a low value for the GCPs and a higher value for the cameras

17

General / Re: Accuracy in Orthomosaic Output is not coming

« on: February 04, 2023, 09:34:44 AM »

Are you using ground control points? And are you sure the coordinates of the GCPs are accurate?

18

General / Re: Agisoft Metashape 2.0.0 pre-release

« on: January 29, 2023, 09:42:22 PM »

This may seem like a minimal thing to look for, but the change of "Build Dense Cloud" to "Build Point Cloud" is fine, but now the order in the Workflow dropdown is out of order it seems and can be confusing. it is nice to have the workflow items in order of common workflow process order. Now Build Point Cloud is below Build Tiled Model.

Dear smiller,
Thank you for your feedback.

Usually, when building a model and a tiled model, users can skip building a point cloud and use depth maps as source data. Users who need a point cloud as a result usually process aerial data, after that they build DTM/DSM, Orthomosaic. Therefore, the workflow is divided into such sections and the order of commands has been changed.

I know this is off topic but could you consider having the workflow be buttons on the interface, rather than in a menu?

19

General / Flying manually and rolling shutter compensation

« on: January 29, 2023, 09:40:24 PM »

I fly my DJI Air 2S and DJI Mini 3 manually, and I try to get all my photos while the drone is moving forward. But sometimes I accidentally take a picture while the drone is stationary. Or I intentionally take  some photos with the drone stationary to get some different angles on a particular building or natural feature. Do I need to split these photos into a separate group so they don't get rolling shutter compensation applied?

20

General / Re: Linear features - flight lines

« on: January 10, 2023, 08:51:28 AM »

Fly along the jetty directly above, and fly additional lines on each side of it

21

General / Re: Usage of reference points as ground points

« on: January 10, 2023, 07:58:56 AM »

Do you mean you took GPS coordinates of locations on the ground without markers? You can use those as control points, you just have to place them correctly on the images

22

General / Re: Orthomosaic from large aerial dataset issues

« on: November 27, 2022, 10:29:25 PM »

On my viewer you can see my orthomosaics made with the DEM as the base https://arcg.is/1Krum81

23

General / Re: Orthomosaic from large aerial dataset issues

« on: November 27, 2022, 07:06:36 AM »

I haven't created any orthomosaics from that many photos but what I always do is make a medium or high quality dense cloud, then create the DEM, and then the orthomosaic. I don't ever make a 3D model first, unless I want my final product to be a 3D model

24

General / Re: How to use GPS/INS Offset settings

« on: October 02, 2022, 10:35:57 PM »

Yes,

in the case of a known fixed offset from camera  center to GNSS antenna like for example the Phantom4, the measured offset in Z is 17 cm and can be input in camera calibration if your airborne GNSS positions refer to antenna.

In case of varying barometric altitudes from DJI, this offset is variable and so using a fixed off set would not be appropriate...

Hope this makes sense!

But it's not variable, or it's only slightly variable. My thinking is that the offset at least reduces the error introduced by the massive offset in the EXIF data

From testing it seems like I was right. When I have metadata values low by 60 meters, I have to put in +60 meters in that field

25

General / Re: How to use GPS/INS Offset settings

« on: September 26, 2022, 06:45:14 AM »

Hi DayGeckoArt,

DJI drones are known to have very inaccurate elevation (taken from barometer). To fix this Z offset, you use following script https://github.com/agisoft-llc/metashape-scripts/blob/master/src/add_altitude_to_reference.py

Hope this helps,

Thanks, this is simple because it spells out what is being done, the value you put in is added.

But is there a reason not to use the camera calibration dialogue to change heights?

26

General / How to use GPS/INS Offset settings

« on: September 25, 2022, 05:56:04 AM »

I've searched and read the manual and I can't find anything clear. My DJI Air 2S drone usually has wildly inaccurate elevation data, possibly because of the datum it's using. Usually it's about 75 meters below where it should be. For example when I take a photo at ground level at 5 meters elevation, the value in the exif data is -70 meters.

How do I adjust this in Camera Calibration? According the manual it seems like I would put in -75 but that seems backward. Should I put in +75 to add 75 to the exif value?

27

Camera Calibration / Re: Adaptive camera model or calibration groups

« on: August 07, 2022, 10:02:17 AM »

Is there a way to select or sort photos by speed and direction of drone flight so that each group can get different rolling shutter corrections? I can't even find a way to view the metadata that shows speed

I don't think so, except maybe through python scripting, but what might help is that you can select photos using the 3D/Model tab or normal photos pane, and then open the camera calibration window, and any photos that were selected before will now be selected in the list at the bottom of the calibration window, though you may have to scroll down to find them.

Still doesn't help you filter by speed or direction, but it may be easier to identify and select these photos intuitively in the 3D view before you go into camera calibration.

THANK YOU, that helps a lot because the gallery view makes it easier to go through and find the ones where they're in a sequence so you can tell it was with the drone moving

28

Camera Calibration / Re: Interior camera calibration based on single image and many GCPs

« on: August 01, 2022, 04:23:07 AM »

Yes, I would mark the control points in every photo they appear in, then optimize or run a new camera alignment. Then save the camera calibration to CSV file and you can load it in later projects. When you run the photo align, the Agisoft uses that calibration data but will also adjust it for the new new project

29

Camera Calibration / Re: Adaptive camera model or calibration groups

« on: July 31, 2022, 03:19:46 AM »

In the lower right of the 'Camera Calibration' window is a list of all the photos in each group. You can select the photos you want to move to a new group, right click and select 'Create Group'.

Thank you, I never would have found that. My workaround was to split the group on the left window which would make each photo its own group, then select on that side and group them.

I have another question. I have an Air 2S and I fly manually and often have different speeds because of wind. Today I even flew backward for many photos because the drone kept losing signal when I turned it. Is there a way to select or sort photos by speed and direction of drone flight so that each group can get different rolling shutter corrections? I can't even find a way to view the metadata that shows speed

30

Camera Calibration / Re: Adaptive camera model or calibration groups

« on: July 20, 2022, 02:59:36 AM »

How do you calibrate groups separately?

I have some photos flown at 15 meters per second speed and some at 5 meters per second so I want different rolling shutter correction.

I have them in two different groups. But there seems to be no method to set different calibration. In the Camera Calibration dialog I can only split the group so each camera is its own group