Compensation of random eye motion in television ophthalmoscopy: preliminary results

Involuntary eye movements make the observation of the ocular fundus on a TV monitor fatiguing for the physician, not to mention the practical impossibility of measuring dynamic phenomena such as the venous pulse observed in a sensible percentage of patients. It is therefore necessary to measure and compensate, for display and analysis, the displacement between each image in the video sequence and a reference one. This paper reports the results of a preliminary set of registration experiments, carried out on low quality photographs of the ocular fundus obtained without contrast medium. The results confirm the robustness of the chosen approach, phase correlation. The effects of choices such as computer word length or raw-data windowing on system performance are also analyzed.