Segmentation of optic disc and optic cup in colour fundus images based on morphological reconstruction

Glaucoma disease is one of the retinal abnormalities caused by size changing of optic disc and optic cup. The disease is commonly diagnosed by quantifying vertical cup-to-disc ratio (CDR). Therefore, this study proposes two schemes for segmenting optic disc and optic cup based on morphological reconstruction. Retinal vessel removal is considered during the process. The proposed schemes are evaluated on 50 colour fundus images collected from Drishti-GS dataset. The final segmentation results are compared to the available ground truth image. Segmentation of optic disc achieves the level of accuracy, sensitivity and specificity at 96.3%, 83.12% and 99.37%, respectively. The evaluation for optic cup segmentation obtains the accuracy of 99.13%, sensitivity of 80.68% and specificity of 99.53%. These successful results in segmenting optic disc and optic cup indicate that the proposed schemes have a potential to be implemented as part of the development of computerised glaucoma diagnosis systems.