1. A computer-implemented method for processing image data, the method comprising: computing, by a processor, a surface displacement field based at least in part on a first, second and third plurality of data points, the first plurality of data points being representative of at least a portion of a reference image, the reference image depicting an object of interest therein, the second plurality of data points being representative of a contour within the reference image, the contour corresponding to the object of interest, the third plurality of data points being representative of at least a portion of a target image, the target image depicting the object of interest therein, the surface displacement field defining a map from the second plurality of data points to a fourth plurality of data points, the fourth plurality of data points representative of a contour within the target image, the target image contour corresponding to the object of interest.