Assessment of the risk for the development of Age related Macular Degeneration requires reliable detection of retinal abnormalities that are considered s precursors of the disease. A typical sign for the later are the so-called drusen, which appear as abnormal white-yellow deposits on the retina. This paper presents a novel segmentation algorithm for automatic detection of abnormalities in images of the human eye’s retina, acquired from a depthvision camera. Conventional image processing techniques are sensitive to non-uniform illumination and nonhomogeneous background, which obstructs the derivation of reliable results for a large set of different images. Homomorphic filtering and a multilevel variant of histogram equalization are used for non-uniform illumination compensation and enhancement. We develop a novel segmentation technique, the Histogram-Based Adaptive Local Thresholding (HALT), to detect drusen in retina images by extracting the useful information without being affected by the presence of other structures. We provide experimental results from the application of our technique to real images, where certain abnormalities (drusen) have slightly different characteristics from the background and are hard to be segmented by other conventional techniques.
International Conference on Image Processin, Volume 3, pp.1055-1058, October 2001.
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