Fig. 2
From: A general geometric transformation model for line-scan image registration
Distance change from the optical centre to the planar object of the line-scan camera under parallel relative motion direction and arbitrary relative motion direction. a The motion direction of the line-scan camera is parallel to the imaged object; the distance z1, z2 and z3 from the optical centre to the object does not change with the relative motion. b The line-scan camera moves in any direction relative to the imaged object; the distance z1, z2 and z3 from the optical centre to the object changes with the relative motion