Definition of extrinsic here

[scy639]

The extrinsic here is c2w (camera to world matrix. Xw = Mc2w @ Xc), not w2c ?

[Wuziyi616]

Yeah I got weird visualization results using w2c. When using c2w it seems to make more sense. Have you figured this out?

[scy639]

Yeah I got weird visualization results using w2c. When using c2w it seems to make more sense. Have you figured this out?

Yes. I think the extrinsic in this project has 2 possible explanations that make sense:

1. It is w2c, but is defined for row vector, which means that: Xc= extrinsic @ Xw, where Xc and Xw are both row vector ( I guess this is what the author meant )
2. It is c2w : Xw = extrinsic @ Xc, where Xc and Xw are both column vector

Both explanations are consistent with the code in this project: vertex_transformed = vertex_std @ extrinsic.T and yield correct visualization results.

[Wuziyi616]

Thanks, I just use the common c2w matrix (which is basically np.linalg.inv(w2c)) and that seems to work : )

[verdureB]

i also think it is c2w，because the project defines a pyramid on the camera coordinate system.if use input(c2w),can transform coordinates of pyramid (in the camera coordinate system)into world coordinate system.So, We can obtain the extrinsic parameter pose of each camera.

[haowang020110]

I also think it is c2w