1. A method of establishing image registration between a two-dimensional optical coherence tomography image and a three-dimensional optical coherence tomography image, comprising the steps of: (A) obtaining the two-dimensional image via a pre-defined scanning protocol such that the two-dimensional image includes a portion of an eye; (B) obtaining the three-dimensional image such that the three-dimensional image includes said portion; then, (C) in the three-dimensional image, delineating a region of interest within said portion; then (D) re-sampling said region with said pre-defined scanning protocol to generate at least one two-dimensional re-sampled image; then, (E) in each of said two-dimensional image and said re-sampled image, detecting at least one feature of interest common to both images; then (F) correlating between said feature in said two-dimensional image and said re-sampled image, respectively, with respect to at least one similarity measure to identify a location on said feature in said two-dimensional image and said re-sampled image, respectively, wherein said location exhibits the highest value of said measure; and then (G) establishing image registration between said re-sampled image and said two-dimensional image, based on spatial information about said location.