# Using findHomography to create 'fake' intrinsics?

I have two images from very different cameras.

```
cv::Mat CameraA is from a 16mm lens, and the resolution is 1920 * 1080
cv::Mat CameraB is from a 7mm lens, and the resolution is 1280 * 720
```

I have calibrated these, and used a chessboard with solvePnP to get poses.

Now, i want to pass these into a bundle adjustment function, using cvsba.

BUT, the function expects the same intrinsics from both cameras.

If I was to use findHomography to get an H matrix from the sets of 2d points, and then scale CameraA to match CameraB, would I then be able to use the intrinsics from CameraB for CameraA?

If not, is there a way to somehow 'normalise' intrinsics in this way?

Thank you.

I would try two things:

`(x,y,z=1)`

and pass identity camera matricesHi, thank you for getting back to me. Can you please explain the second option for me? How do I

`compute the image coordinates in normalized camera coordinates`

? Is an identity intrinsic matrix zeros, with`1`

for`fx,fy,cx,cy`

? Thanks!Is this the correct approach?

I think so.

To be sure, just project the undistorted point with the real camera intrinsics and you should get more or less your 2D image coordinates.