The rectified image with the pinhole model 8 parameters will have curved boundary

[yunlongwang-leopard]

System Information

OpenCV version: 4.9.0.80
Operating System / Platform: windows10
Python version: 3.10.13

Detailed description

we use the pinhole model 8 parameters to do calibration.
When calibrated with 8 parameters, the corrected graph will have a boundary,if we use 5 parameters, it has no boundary.
some calibration file will have such case with 8 parameters while others will not.

calibration_demo.zip

Steps to reproduce

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)

[yunlongwang-leopard]

why is it closed? @asmorkalov can you explain it?

[asmorkalov]

It's not clear how the intrinsics were calibrated. The undistorting result depends on it