Readings
Bergen et al.  Hierarchical model-based
motion estimation. ECCV’92,  pp. 237–252.
Szeliski, R.  Image Alignment and Stitching:
A Tutorial, MSR-TR-2004-92, Sec. 3.4 & 3.5.
Shi, J. and Tomasi, C. (1994). Good features
to track. In CVPR’94, pp. 593–600.
Baker, S. and Matthews, I. (2004). Lucas-
kanade 20 years on: A unifying framework.
IJCV, 56(3), 221–255.