Automatic location of optic disk in retinal images

On the research work leading to automatic analysis of retinal fundus images, the knowledge of the optic disk location is essential, and a new method to locate the optic disk automatically is proposed. The candidate regions are first determined by clustering the brightest pixels in the intensity image. Principal component analysis (PCA) is then applied to these candidate regions. The minimum distance between the original retinal image and its projection onto "disk space" is located as the center of the optic disk. The algorithm has been tested and compared with another commonly used method and the results show that the method proposed here can provide more acceptable automatic location of the optic disk.