Messages

1

General / Re: Controlling non-RTK data using RTK sensor data of the same area

« on: July 03, 2023, 11:15:14 AM »

Thanks, that makes sense. However, that negates the accuracy benefits of the Sony, and flying at 300m isn't feasible without a very expensive OSC in the UK.

Manually derived GCP from the Sony is the best way forward then, if visible on the Altum.

2

General / Re: To CTL or not to CTL that is the RTK question?

« on: June 30, 2023, 03:22:47 PM »

Thanks Paulo, that makes sense. I fully agree, my curiosity stems from the webinar where Alexey and Wingtra say not to use CTL, just to use any GCP as CHK.

Although my recent, and first, PPK processing without CTL or using 4 CTL didn't make a significant difference in x/y or z. I may need to set up a proper test of this.

3

General / Re: Controlling non-RTK data using RTK sensor data of the same area

« on: June 30, 2023, 11:05:18 AM »

Thanks for posting. I tried that already, MS only aligned the Sony data, not the Altum, unless I got the workflow wrong in MS.

4

General / To CTL or not to CTL that is the RTK question?

« on: June 29, 2023, 06:59:34 PM »

Hi,

When processing imagery with RTK/PPK air control points, what is the best practice re GCP? I've seen a Wingtra webinar where Alexey recommends to only use check points, but an Agisoft guide on this mentions using some CTL. Other sources state that some GCP is still best practice. I'd appreciate your views on this, with regard to Metashape processing. I'm not talking about check points, they are always useful to gauge result accuracy. If CTL are used, what are the priority settings in Metashape, is that controlled through the accuracy settings, as I understand it?

With RTK/PPK Alexey also recommends using Fit additional corrections for PPK data in Optimize, specifying all General parameters, but I've found better results with Adaptive on its own. Tbh, I always use adaptive, without fully understanding when to NOT use it. A simple guide on that would be helpful.

Thanks
M

5

General / Controlling non-RTK data using RTK sensor data of the same area

« on: June 29, 2023, 06:49:46 PM »

Hi,

Given a RTK enabled high-res system (Sony RXII on WingtraOne with PPK in this case) and a non-RTK system (MicaSense Altum on WintraOne Gen 1, hence no PPK) and given that the same area is flown, can the RTK data be used to control the non-RTK data, without manually deriving GCP from the RTK system processed data? When imaging intertidal areas creating GCP is often not possible due to mud/tides/access. In a test case I did have 6 GCP in the area, but not well spread out due to aforementioned constraints. But in future we may not be able to put out GCP.

What would the workflow be here? Can the RTK RGB and MS data be processed together, using the RTK RGB images as a 'scaffold' for the MS in a multi-camera setup?

Thanks
M

6

Python and Java API / Re: Automated PS script to process single or multiple chunks - opinions please

« on: March 21, 2023, 01:06:15 PM »

I've updated the code for 2.0, script v8.0 on github:
https://github.com/gisportsmouth/PhotoScan-Automation-Script

7

Python and Java API / Re: Automated PS script to process single or multiple chunks - opinions please

« on: March 18, 2023, 09:22:01 AM »

Hi

The script was last updated for version 1.8. There must have been changes to the Python API in the update to v2 which break the script, hence the error.
I will look at this and update the script when I have time, hopefully next week
I'll also need to check why the major version check didn't flag this as an issue.

Cheers

8

General / Re: Waving a white flag

« on: June 10, 2022, 01:20:45 PM »

Refine markers does indeed work for this workflow, white flags turn blue as an image is loaded after the initial points are manually defined, thanks.

Not sure what you mean about the names not being important, please clarify. I need to match the names to update the coordinates from the GCP file. (That's a minor issue, as you can edit the GCP csv to match the labels, i.e. "point 1".)

In the import reference dialogue there is a checkbox that "ignore labels", try it and you will understand. Metashape manages to match markers and ground points on its own (obviously it can fail if points distribution is too much regular making several matches plausible)
Also you may need to see if by enabling "refine markers" under tools menu, you get the boost you want for your workflow. (also needs some user care, that is why it is not enabled by default)
Best regards,

José Martínez
Geobit & Accupixel
Metashape traning

9

General / Re: Waving a white flag

« on: June 10, 2022, 12:55:52 PM »

Exactly what I was looking for, thanks Alexey

Hello Martin,

The following code should create marker projections (blue flags) on the images, based on the marker 3D location, which can be defined either by the reference coordinates only, or by other manually placed projections:

Code: [Select]

import Metashape
chunk = Metashape.app.document.chunk #active chunk
for marker in chunk.markers:
if not marker.position:
continue
point = marker.position
for camera in [c for c in chunk.cameras if c.transform and c.type == Metashape.Camera.Type.Regular]:
if camera in marker.projections.keys():
continue #skip existing projections              
x, y = camera.project(point)
if not(x) or not(y):
continue
if (0 <= x < camera.sensor.width) and (0 <= y < camera.sensor.height):
marker.projections[camera] = Metashape.Marker.Projection(Metashape.Vector([x,y]), False)
print("Script finished")
Is it what you are looking for?

10

General / Re: Waving a white flag

« on: June 09, 2022, 12:41:49 PM »

Thanks for the response

To clarify, green marker=user placed, blue marker=system placed, both used in processing, white marker=system placed but not used in processing, that's understood. I also understand I need to check all blue flags, as mentioned in the OP.

Correct me if I'm wrong, Add Marker adds a marker and works out the projections on the other images, Place marker adds it in 2D on that image only.

Not sure what you mean about the names not being important, please clarify. I need to match the names to update the coordinates from the GCP file. (That's a minor issue, as you can edit the GCP csv to match the labels, i.e. "point 1".)

At the moment you have two workflows as I see it, and my question is if they can be merged, as both are cumbersome in their own way.

WF1 - using add markers: Add marker by right clicking on each marker once, move a few blue flags, check the others and leave them if good enough. Then load GCP file with matching names to update the coordinates of the markers to the GCP. Issues are that you need to find each GCP, not always easy on e.g. glacial rubble.

WF2 - using a GCP file: Load GCP file, some white flags pop up, if you fix about 4 in place and Update Transform all other GCP are roughly located, which is better in terms of finding them. After manually updating a couple of markers each the others show up in the right place, but need to be clicked on to turn green. With several markers on several images each that's a lot of clicking.

So my question is, can you use the gcp workflow and get blue flags, best of both worlds.

This is not a big issue, but I'm trying to find the most efficient way of marking GCP, just tired of clicking markers, either way.

11

General / Waving a white flag

« on: June 08, 2022, 05:52:10 PM »

Hi,

 When adding markers, if a markers are placed you get an automatically aligned blue flag on the other images it appears on. They still need to be checked, but are often ok, making the process less manually intensive.

 When loading a GCP file and placing a marker the flags never turn blue, they are white, and not used in processing. You need to click on every white flag to turn it green. Now, you can add points, rename them to match your markers, and then load the coordinates later, but that's cumbersome. Is there a way to turn the white flags blue, mirroring the add points workflow? I ask this before I spend time coding some python to turn flags green.

Cheers
M.

12

Python and Java API / Re: Automated PS script to process single or multiple chunks - opinions please

« on: May 10, 2021, 06:02:18 PM »

TBH, I can't remember why it is False. This script develops as and when I need it, SfM is only a small part of what I do. I'll look into it when I next edit it, but you seem to have the skill to develop it further for your needs.

13

Python and Java API / Re: Automated PS script to process single or multiple chunks - opinions please

« on: May 07, 2021, 06:23:03 PM »

Thanks Paul, I'll look at your version and perhaps merge them.

The maintained version is on Github:
https://github.com/gisportsmouth/PhotoScan-Automation-Script

14

Python and Java API / Re: Automated PS script to process single or multiple chunks - opinions please

« on: March 15, 2019, 05:11:19 PM »

Hi Luiz,

 Thanks for your code. Not been able to do much on this lately, and to go through your code properly, but have updated to accommodate Metashape and some minor tweaks. Thought I'd share until I have more time.

Cheers
Martin

15

Python and Java API / Re: Automated PS script to process single or multiple chunks - opinions please

« on: February 07, 2019, 06:17:34 PM »

Hi Luiz,

 thanks for commenting. PhotoScan doesn't seem to update the points until the model is optimised.

 The approach in your second post works, but only until the session is shut down. Tracks would allow you to re-open the document later and carry on. But tracks give all points, what I'm really after is the valid points after alignment. I might not change to tracks because of this. I've made a few changes to the code and am testing, will possibly upload a newer version soon-ish.

Cheers