error when using "model merger"

[coconiox2]

error when using model merger

I used colmap-GUI to do a sparse reconstruction on two data sets with intersecting images.But I had a problem with the model_merger process.

./colmap model_merger --input_path1 /home/hadoop/data/1_space --input_path2 /home/hadoop/data/2_space --output_path /home/hadoop/data/fuse

Reconstruction 1
Images: 40
Points: 45907

Reconstruction 2
Images: 40
Points: 52919

Merging reconstructions
F1113 22:32:54.185003 28747 reconstruction.cc:633] Check failed: Image(image_id).Name() == reconstruction.Image(image_id).Name() (DJI_0240.jpg vs. DJI_0228.jpg)
*** Check failure stack trace: ***
@ 0x7fa1e2b1f5cd google::LogMessage::Fail()
@ 0x7fa1e2b21433 google::LogMessage::SendToLog()
@ 0x7fa1e2b1f15b google::LogMessage::Flush()
@ 0x7fa1e2b21e1e google::LogMessageFatal::~LogMessageFatal()
@ 0x683f7e colmap::Reconstruction::FindCommonRegImageIds()
@ 0x69f8fe colmap::ComputeAlignmentBetweenReconstructions()
@ 0x68ea3d colmap::Reconstruction::Merge()
@ 0x5d309f RunModelMerger()
@ 0x5bb2fe main
@ 0x7fa1df1c2840 __libc_start_main
@ 0x5c51a9 _start
@ (nil) (unknown)
已放弃 (核心已转储)

Another question

I want to run colmap on the cluster.First, I distributed the image to the child node, and then sent the result back to the master node for merging after sparse reconstruction on the child node.What should I do?

[tsattler]

I would assume that the model_merger tries to identify images in the two models based on their image ids, i.e., it assumes that images having the same id are identical. It then checks whether the file names are the same. Since this does not seem to be the case, it crashed. I would assume that you are using different databases in the child node.
Potential solutions are:

• Use the same database in each child node, but only use a subset of all images for reconstruction (the mapper has a flag that lets you select a subset of images for reconstruction).
• Adapt the code of the model_merger to identify corresponding images based on their filename and not their image id.

[coconiox2]

Thanks a lot. It works.But I have another question:
If my images are unordered, how should I divide the list of images to make sure that there is enough overlap between the different models?I wonder if Colmap has this function.And what if I could use GPS information to get which images are spatially adjacent?

[tsattler]

You could have a look at the hierarchical mapper, which does some form of subdivision.

[jeojeda]

Hello. Is it possible to merge models using the COLMAP.bat portable version?
I can't find the option.

[tsattler]

Yes, if you call COLMAP.bat from the power shell with the model_merger option.