Tracking cataract by the 'four-line' method
Hanna KJ., Tarassenko L.
An implementation of Scott's 'four-line' algorithm for estimating optic flow is presented. The application is the analysis of cataract motion in the human eye lens. Images are recorded using retro-illumination photography. Successive images recorded at up to a six month interval are used as the source for the flow recovery procedure. The four-line algorithm is applied to edge data from these images at several scales. A procedure for performing image registration and optic flow recovery using the same fourline algorithm is presented. Several examples of the algorithm output are given. © 1989.