Objective: To investigate fast method of automatically positioning central fovea of macula in the images of eye fundus. Methods: A new method, which using iterative threshold changing combined with the localization of retinal vascular trunk and optic disc (OD), was proposed to locate on the central fovea of macula. First, the retinal vascular trunk was extracted by morphological transformation and connected domain computing. And then, 1% point of highest gray level of images was selected as the candidate of region of interest (ROI) of the OD, and the nearest bright area away main skeleton of blood vessel was further screened from them as ROI of OD, and the center and radius of OD were recognized through morphology processing, threshold transform and Hough transform and other steps. Finally, the ROI of the macula was established nearby 2.5 times of the radius of OD, and the isoheight of gray level were constructed by adopting iterative threshold value so as to determine the center of central fovea of macula. Used this method to test 240 images of eye fundus of our hospital. Result: In this test of 240 images of eye fundus by using this method, the accurate rate of positioning central fovea of macula reached to 97.1%. Conclusion: Based on experiment data, the proposed method could locate on the position of central fovea of macula in the images of eye fundus and it has better accuracy and applicability.
China Medical Equipment