Purpose: To introduce AGLAIA, a system to automatically segment the optic cup and the optic disc, which are used to calculate the cup-to-disc ratio (CDR) from 2D digital fundus images for glaucoma diagnosis.
Methods: We propose an A-Levelset algorithm to overcome the limitations of traditional level set-based algorithms in image segmentation. A-Levelset cascades level set with ASM (Active Shape Model) algorithm and uses ASM to fine-tune the outcome of the level set algorithm. A-Levelset algorithm is performed in the following three steps:
- First Step: Run level set algorithm over the image to obtain the segmented object;
- Second Step: Register the level set segmented object with the ASM mean shape;
- Third Step: Run ASM with the registered mean shape as the initial contour to get the fine-tuned segmented object. The AGLAIA system uses the A-Levelset algorithm to segment the optic cup and the optic disc from 2D digital fundus images for glaucoma diagnosis.