System Information

OpenCV version: Latest on GitHub
Operating System: All
Compiler & compiler version: Non-applicable

Detailed description

Expected behaviour

When specifying maxIters to findessentialmat I would expect this to always be the maximal number of iterations. This is already the case for findFundamentalMat (for all methods) and findEssentialMat (when not using usac methods).

Actual behaviour

When using usac, maxIters is always set to 1000. This is clear from the following lines:

Steps to reproduce

The following code snippet will return the exact same results, which is unreasonable.

In Python:

cv2.findEssentialMat(
        kpts0, kpts1, np.eye(3), threshold=norm_thresh, prob=conf, method=cv2.USAC_MAGSAC, maxIters = 1
    )

cv2.findEssentialMat(
        kpts0, kpts1, np.eye(3), threshold=norm_thresh, prob=conf, method=cv2.USAC_MAGSAC, maxIters = 5000
    )

While

cv2.findEssentialMat(
        kpts0, kpts1, np.eye(3), threshold=norm_thresh, prob=conf, method=cv2.RANSAC, maxIters = 1
    )

cv2.findEssentialMat(
        kpts0, kpts1, np.eye(3), threshold=norm_thresh, prob=conf, method=cv2.RANSAC, maxIters = 5000
    )

Produces different results, which is reasonable.

Issue submission checklist

• I report the issue, it's not a question
• I checked the problem with documentation, FAQ, open issues, forum.opencv.org, Stack Overflow, etc and have not found any solution
• I updated to the latest OpenCV version and the issue is still there
• There is reproducer code and related data files (videos, images, onnx, etc)