Research Article

Automatic Optic Disc Detection in Color Retinal Images by Local Feature Spectrum Analysis

Figure 6

Local feature spectrum analysis. (a1–a4) Original optic disc and nonoptic disc images; (b1–b4) patch segmentation with pixels; (c1–c4) reconstruction results of original images; (d1–d4) the error images between the original images (a1–a4) and the reconstructed images (c1–c4); (e1–e4) local feature spectrum analysis results for (a1–a4), respectively.