- camera calibration = estimating instrinsics K (pinhole camera) (camera parameters) by measuring
- real world points X in world space
 - same points in pixel space
 - solving for K[R|t] using singular value decomposition (SVD) after posing problem as 
- where p = camera params
 - A is from mapping to
 
 
 - pose estimation: estimating extrinsics [R | T]
 
see camera intrinsics and extrinsics
can use vanishing points to estimate calibration