Glaucoma is a disease characterized by elevated intraocular pressure (IOP). This increased IOP leads to damage of optic nerve axons at the back of the eye, with eventual deterioration of vision. CDR is a key indicator for the detection of glaucoma. The existing approaches determined the CDR using manual threshold analysis which is fairly time consuming. This paper proposes two methods to extract the disc automatically. The component analysis method and region of interest (ROI) based segmentation are used for the detection of disc. For the cup, component analysis method is used. Later the active contour is used to plot the boundary accurately. This method has been tested on numerous image data sets from Madurai Eye Care Centre, Coimbatore.