Exudate Detection and Segmentation Using a Colour and Illumination-Invariant HSV Model for Diabetic Retinopathy Classification
摘要
Diabetic retinopathy is a significant cause of vision loss; thus, accurately detecting exudates is essential for early diagnosis. However, exudates often resemble other retinal features such as the optic disc and haemorrhages, making automated segmentation challenging. Therefore, this study proposes a Hue-Saturation-Value (HSV) colour-based segmentation framework with preprocessing steps including Contrast Limited Adaptive Histogram Equalisation (CLAHE)-based contrast enhancement and optic disc masking to avoid false positives. Yellow exudates were segmented using optimised hue saturation thresholds. The approach was validated on the IDRID (Indian Diabetic Retinopathy Image Dataset) dataset, with evaluation based on pixel-level accuracy metrics. The method achieved 93.5% accuracy, 90.3% sensitivity, 93.3% specificity, 84.7% precision, 87.4% Dice score, and 77.6% Intersection over Union (IoU), demonstrating effective exudate localisation while reducing optic disc-related errors. The proposed framework provides reliable exudate segmentation and can serve as a preprocessing step for deep learning–based DR classification.