How to calculate K0

[davidretinski]

Hello, I am currently trying to use your algorithm. I was wondering how you calculated K0? This is the intrinsic matrix for the reference image. The reference image in turn is a section of a scene image, right?

[werdnabae]

I'm interested in this too. I'm guessing they adjusted the intrinsic matrix based off of how they cropped + resized the reference image from the cluttered scene image.
https://stackoverflow.com/questions/74749690/how-will-the-camera-intrinsics-change-if-an-image-is-cropped-resized