1. A computer implemented method for point-to-point measurement of image data, the method comprising: receiving an indication of a pair measurement points within an input image frame; determining a 3D spatial coordinate for each of a plurality of points along a measurement line defined by the pair of measurement points; estimating a multivariate location and scatter of the 3D spatial coordinates associated with the measurement line by computing a minimum covariance determinant (MCD) estimator for the 3D spatial coordinates, the MCD identifying a covariance matrix having the lowest determinant for a predetermined threshold number of the 3D spatial coordinates; determining if the predetermined threshold number of the 3D spatial coordinates are all on a hyperplane; computing a pair of predicted points by: evaluating an equation of the hyperplane at the measurement points in response to the predetermined threshold number of the 3D spatial coordinates all being on the hyperplane; or projecting the measurement points onto a principal component determined from an Eigen decomposition of the scatter, in response to the predetermined threshold number of the 3D spatial coordinates not all being on the hyperplane; determining a Euclidean distance between the pair of predicted points; and storing the distance to a memory in association with the pair of measurement points.