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facebookresearch / ocean

Ocean is the in-house framework for Computer Vision (CV) and Augmented Reality (AR) applications at Meta. It is platform independent and is mainly implemented in C/C++.
https://facebookresearch.github.io/ocean/
MIT License
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Calibration design issue #41

Open ranjitkathiriya544 opened 5 days ago

ranjitkathiriya544 commented 5 days ago

Thanks for the reply,

  1. In pattern calibration, if the pattern is too far from the camera, the calibration will not work effectively.
  2. I have observed that for an image to be detected, more than 80% of the frame should be occupied by the pattern. If it’s less, detection fails.

I have added an example of a patten below, that might failed in scenario.

a

what I have observed, that if you crop a image, in below way then I can be able to detect. That's proofs 2 point.

image

Originally posted by @ranjitkathiriya544 in https://github.com/facebookresearch/ocean/issues/40#issuecomment-2384135730

leapally commented 5 days ago

Hi, @ranjitkathiriya544.

Are you able to move the calibration pattern closer to the camera or print a larger calibration pattern? Could you explain your use case? Maybe that would help us understand the need to have a calibration pattern that takes up a small portion of the camera's field of view.

I'm not terribly familiar with Ocean's square array pattern calibration process, but I imagine that calibration pattern taking up a large portion of the field of view of the camera is desirable. So the behavior you observed may be intentional and true to design rather than a bug.

ranjitkathiriya544 commented 4 days ago

our camera and the pattern distance is 2.6 meters, and also the maximum size of pattern A1.

With OpenCV it works fine, we are comparing the both methods.

ASchneiderMeta commented 3 days ago

I've been able to reproduce your problem with the large image you attached to the Issue. Unfortunately, it turns out that Ocean's calibration pattern detector is not very robust to visible edges that are not part of the pattern itself. If I start with your image and use gimp to fill the red background (and the "Scene" text) with white, the pattern is detected successfully and the code you posted in your now-closed issue seems to work, after correcting the number of columns to 3. For a quick fix, if it's possible to put the calibration pattern in front of a quiet white background, the detector is likely to work better. We will work on making the detector more robust and hope to have an improvement for you next week.

leapally commented 10 hours ago

Hi @ranjitkathiriya544,

Could you share with us the field of view and resolution figures for your camera?

And is this an RGB camera or monochrome? And is there anything special about the lighting conditions or objects visible in the background?