WebODM Code 1 exit with GCPs

Gnardog · 14 April 2019 18:20

Hello,
I am having difficulties processing any images using a GCP file. I have been uploading 49 images and a gcp_list.txt file at the same time. I have tried processing both with my docker machine processing node and the WebODM lightning processing node with no luck. The second I take the GCP file out of the upload the process works and provided all assets in the right location. To reiterate, the DSM/DTM method works when there is no GCP file uploaded with it and fails when the GCP file is uploaded with it. GCP format below

EPSG:4326
gcp01 -105.215613000000005 39.813785000000003 5850.11548
gcp02 -105.216070200000004 39.815163400000003 5780.15371
gcp03 -105.217528900000005 39.814393400000000 5850.12545
gcp04 -105.218942100000007 39.815082799999999 5780.82953
gcp05 -105.219226100000000 39.813940400000000 5880.27859

Mission2_fail

ITWarrior · 14 April 2019 21:09

What does the console say (Console button is next to Simple)?

Have you tried converting the values to WGS84?

You need to put the filename after the altitude also. See the example at the bottom of here:

github.com

mapillary/OpenSfM/blob/main/doc/source/gcp.rst


Ground Control Points
---------------------

When EXIF data contains GPS location, it is used by OpenSfM to georeference the reconstruction.  Additionally, it is possible to use ground control points.

Ground control points (GCP) are landmarks visible on the images for which the geospatial position (latitude, longitude and altitude) is known.  A single GCP can be observed in one or more images.

OpenSfM uses GCP in two steps of the reconstruction process: alignment and bundle adjustment.  In the alignment step, points are used to globaly move the reconstruction so that the observed GCP align with their GPS position.  Two or more observations for each GCP are required for it to be used during the alignment step.

In the bundle adjustment step, GCP observations are used as a constraint to refine the reconstruction.  In this step, all ground control points are used.  No minimum number of observation is required.

GPSs can be specified in two file formats.  If existing, both are loaded.

.. _json-gcps:

JSON file format
~~~~~~~~~~~~~~~~
GCPs can be specified by adding a text file named ``ground_control_points.json`` at the root folder of the dataset. The format of the file should be as follows::

This file has been truncated. show original

Gnardog · 14 April 2019 23:02

ITWarrior,
Thanks for your reply. As far as formatting my gcp_list.txt, I got that from reading this post https://github.com/posm/posm-gcpi/issues/41

Thanks for clarifying the GCP documentation. I will get the file names at the end of the altitude. The documentation recommends having 15 lines after the header. Which would be 5 GCPs referenced from 3 different pictures each. I will start on that now.

In the mean time, here is the error from the command console

mikegf · 15 April 2019 11:52

I actually had no luck at all with WGS84 GCPs when I started. I ended up converting to UTM. Example of working GCP (and how I do it) is in this post GCP’s not aligning

Gnardog · 15 April 2019 23:36

mikegf/ITWarrior - Thank you both for your replies as they both helped me in a combination of ways. The images needed to be added into each line of my GCPs and my degree lat long needed to be in WGS84 UTM.

Another item I was missing was the img_x and img_y. I could not find a way to get pixel coordinates other than using the GCP interface in webODM.

Thank you again for your help!

Gnardog