I'm working on a problem to find the camera position in the world system when each picture was shot.I currently have several pictures taken from different angles, and for each picture there is only a black square on a white paper. I have the actual size of the black square on the paper and the intrinsic matrix of the camera. And since the square is very easy to crop from each image, I can also obtain the perspective transformation matrix for each image. But I think to eventually find the camera position, the key is to get the extrinsic matrix of the camera. What I've researched is that we need to use a chessboard, but I wonder if I can continue my work without using that.
How to obtain the camera extrinsic matrix without using chessboard
computer vision