A model-based scan line encoder is disclosed. A method of model- based scan line encoding includes defining a geometry model (502) for describing a scan line of a scan, the scan line including multiple scan points (506). The method further includes calculating a trajectory model representing an approximate pattern of deviation (510) of the multiple scan points (506) relative to the geometry model (502). The method further includes calculating multiple residuals, each of the residuals associated with a difference between the deviation (510) of the scan points (506) and the trajectory model. The method may further include compressing the residuals.