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Author Topic: Number of Keypoints  (Read 1025 times)

Isabella

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Number of Keypoints
« on: August 27, 2020, 03:52:30 PM »
Hi all,

I would like to know if (and how) it is possible to check the number of Key Points (not Tie Points) extracted in each image.
Thank you so much for your answer! :)

Cheers
Isabella

PROBERT1968

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Re: Number of Keypoints
« Reply #1 on: August 30, 2020, 05:51:50 PM »
What are you working on ?

 Are you using any geospatial images to use such as old aerial photos ,  current drones photographs ?

or working on some other non-geospatial images such as structure, cars,  houses , buildings ?

and welcome to Agisoft Metashape forum

I work a lot of old historical aerial images and i usually use very high like at least 80,000 but when I look it up on google on that issue and i get many different answers...


« Last Edit: August 30, 2020, 06:05:10 PM by PROBERT1968 »

JMR

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Re: Number of Keypoints
« Reply #2 on: August 31, 2020, 02:49:31 PM »
Yes. you can dig into project folder structure and find a file called doc.xml inside of the latest point.cloud folder located in project.files/0/0
There is a slight problem that it is to identify image_id with its label or file name. You need to open another one, equally called doc.xml packed inside the chunk.zip folder, located in project.files/0/

There must be a simpler way by means of python console, but I can't help with that.
Best
GEOBIT

Isabella

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Re: Number of Keypoints
« Reply #3 on: September 10, 2020, 01:41:22 PM »
Thanks for your suggestions!

Digging into the project folder, I could check the doc.xml file that you pointed out. However, I could not find the number of Keypoints (only the number of tracks and successfully matched TieP seems to be recorded there), and I could not open the kpt file(s) referred to as keypoints files.

Does this make sense or did I miss something?

Thanks again for your help,
Best
Isabella

Alexey Pasumansky

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Re: Number of Keypoints
« Reply #4 on: September 11, 2020, 11:34:09 AM »
Hello Isabella,

At the moment there's no straightforward way to access the number of key points for certain camera. We will consider such feature in Python API in future releases, though.

Possible approach is to analyze the start of the image matching log, where each line corresponds to the camera.key value:
Code: [Select]
2020-09-11 11:34:32 Matching photos...
2020-09-11 11:34:32 Detecting points...
2020-09-11 11:34:32 Found 1 GPUs in 0 sec (CUDA: 0 sec, OpenCL: 0 sec)
2020-09-11 11:34:32 Using device: GeForce GTX 980 Ti, 22 compute units, free memory: 2219/6144 MB, compute capability 5.2
2020-09-11 11:34:32   driver/runtime CUDA: 11000/8000
2020-09-11 11:34:32   max work group size 1024
2020-09-11 11:34:32   max work item sizes [1024, 1024, 64]
2020-09-11 11:34:33 [GPU] photo 6: 5624 points
2020-09-11 11:34:33 [GPU] photo 8: 5456 points
2020-09-11 11:34:34 [GPU] photo 3: 5524 points
2020-09-11 11:34:34 [GPU] photo 9: 5524 points
2020-09-11 11:34:34 [GPU] photo 10: 5626 points
2020-09-11 11:34:35 [GPU] photo 5: 5097 points
2020-09-11 11:34:35 [GPU] photo 11: 5097 points
Best regards,
Alexey Pasumansky,
Agisoft LLC

Isabella

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Re: Number of Keypoints
« Reply #5 on: September 11, 2020, 01:23:26 PM »
Thanks for the quick answer.
As suggested, I will check the information recorded in the Console.

Regards and thanks
Isabella